diff --git a/common.go b/common/common.go
similarity index 98%
rename from common.go
rename to common/common.go
index b4523d0..92ec34f 100644
--- a/common.go
+++ b/common/common.go
@@ -52,7 +52,7 @@ func readLinesOffsetN(filename string, offset uint, n int) ([]string, error) {
 	return ret, nil
 }
 
-func byteToString(orig []byte) string {
+func ByteToString(orig []byte) string {
 	n := -1
 	l := -1
 	for i, b := range orig {
diff --git a/common_darwin.go b/common/common_darwin.go
similarity index 87%
rename from common_darwin.go
rename to common/common_darwin.go
index 3707636..7a742bd 100644
--- a/common_darwin.go
+++ b/common/common_darwin.go
@@ -7,7 +7,7 @@ import (
 	"strings"
 )
 
-func doSysctrl(mib string) ([]string, error) {
+func DoSysctrl(mib string) ([]string, error) {
 	out, err := exec.Command("/usr/sbin/sysctl", "-n", mib).Output()
 	if err != nil {
 		return []string{}, err
diff --git a/common_freebsd.go b/common/common_freebsd.go
similarity index 87%
rename from common_freebsd.go
rename to common/common_freebsd.go
index d1e2a6e..997bb78 100644
--- a/common_freebsd.go
+++ b/common/common_freebsd.go
@@ -7,7 +7,7 @@ import (
 	"strings"
 )
 
-func doSysctrl(mib string) ([]string, error) {
+func DoSysctrl(mib string) ([]string, error) {
 	out, err := exec.Command("/sbin/sysctl", "-n", mib).Output()
 	if err != nil {
 		return []string{}, err
diff --git a/common_windows.go b/common/common_windows.go
similarity index 93%
rename from common_windows.go
rename to common/common_windows.go
index e84abc3..af6b2e8 100644
--- a/common_windows.go
+++ b/common/common_windows.go
@@ -21,7 +21,7 @@ type FILETIME struct {
 }
 
 // borrowed from net/interface_windows.go
-func bytePtrToString(p *uint8) string {
+func BytePtrToString(p *uint8) string {
 	a := (*[10000]uint8)(unsafe.Pointer(p))
 	i := 0
 	for a[i] != 0 {
diff --git a/cpu.go b/cpu/cpu.go
similarity index 100%
rename from cpu.go
rename to cpu/cpu.go
diff --git a/cpu_darwin.go b/cpu/cpu_darwin.go
similarity index 97%
rename from cpu_darwin.go
rename to cpu/cpu_darwin.go
index 6d2ba56..cb03fb8 100644
--- a/cpu_darwin.go
+++ b/cpu/cpu_darwin.go
@@ -7,6 +7,8 @@ import (
 	"os/exec"
 	"strconv"
 	"strings"
+
+	common "github.com/shirou/gopsutil/common"
 )
 
 // sys/resource.h
@@ -37,7 +39,7 @@ func CPUTimes(percpu bool) ([]CPUTimesStat, error) {
 		ncpu = 1
 	}
 
-	cpuTimes, err := doSysctrl(sysctlCall)
+	cpuTimes, err := common.DoSysctrl(sysctlCall)
 	if err != nil {
 		return ret, err
 	}
diff --git a/cpu_freebsd.go b/cpu/cpu_freebsd.go
similarity index 97%
rename from cpu_freebsd.go
rename to cpu/cpu_freebsd.go
index 2d5df5e..f1055bf 100644
--- a/cpu_freebsd.go
+++ b/cpu/cpu_freebsd.go
@@ -7,6 +7,8 @@ import (
 	"regexp"
 	"strconv"
 	"strings"
+
+	common "github.com/shirou/gopsutil/common"
 )
 
 // sys/resource.h
@@ -37,7 +39,7 @@ func CPUTimes(percpu bool) ([]CPUTimesStat, error) {
 		ncpu = 1
 	}
 
-	cpuTimes, err := doSysctrl(sysctlCall)
+	cpuTimes, err := common.DoSysctrl(sysctlCall)
 	if err != nil {
 		return ret, err
 	}
diff --git a/cpu_linux.go b/cpu/cpu_linux.go
similarity index 100%
rename from cpu_linux.go
rename to cpu/cpu_linux.go
diff --git a/cpu_test.go b/cpu/cpu_test.go
similarity index 100%
rename from cpu_test.go
rename to cpu/cpu_test.go
diff --git a/cpu_windows.go b/cpu/cpu_windows.go
similarity index 100%
rename from cpu_windows.go
rename to cpu/cpu_windows.go
diff --git a/disk.go b/disk/disk.go
similarity index 100%
rename from disk.go
rename to disk/disk.go
diff --git a/disk_darwin.go b/disk/disk_darwin.go
similarity index 54%
rename from disk_darwin.go
rename to disk/disk_darwin.go
index 95bda72..8b8b7e3 100644
--- a/disk_darwin.go
+++ b/disk/disk_darwin.go
@@ -2,11 +2,15 @@
 
 package gopsutil
 
+import (
+	common "github.com/shirou/gopsutil/common"
+)
+
 func DiskPartitions(all bool) ([]DiskPartitionStat, error) {
 
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 
 func DiskIOCounters() (map[string]DiskIOCountersStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
diff --git a/disk_freebsd.go b/disk/disk_freebsd.go
similarity index 89%
rename from disk_freebsd.go
rename to disk/disk_freebsd.go
index be80297..c415e15 100644
--- a/disk_freebsd.go
+++ b/disk/disk_freebsd.go
@@ -5,6 +5,8 @@ package gopsutil
 import (
 	"syscall"
 	"unsafe"
+
+	common "github.com/shirou/gopsutil/common"
 )
 
 func DiskPartitions(all bool) ([]DiskPartitionStat, error) {
@@ -71,9 +73,9 @@ func DiskPartitions(all bool) ([]DiskPartitionStat, error) {
 		}
 
 		d := DiskPartitionStat{
-			Device:     byteToString(stat.FMntfromname[:]),
-			Mountpoint: byteToString(stat.FMntonname[:]),
-			Fstype:     byteToString(stat.FFstypename[:]),
+			Device:     common.ByteToString(stat.FMntfromname[:]),
+			Mountpoint: common.ByteToString(stat.FMntonname[:]),
+			Fstype:     common.ByteToString(stat.FFstypename[:]),
 			Opts:       opts,
 		}
 		ret = append(ret, d)
@@ -83,7 +85,7 @@ func DiskPartitions(all bool) ([]DiskPartitionStat, error) {
 }
 
 func DiskIOCounters() (map[string]DiskIOCountersStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 
 	// statinfo->devinfo->devstat
 	// /usr/include/devinfo.h
@@ -99,7 +101,7 @@ func DiskIOCounters() (map[string]DiskIOCountersStat, error) {
 
 	ret := make(map[string]DiskIOCountersStat, 0)
 	for _, stat := range fs {
-		name := byteToString(stat.FMntonname[:])
+		name := ByteToString(stat.FMntonname[:])
 		d := DiskIOCountersStat{
 			Name:       name,
 			ReadCount:  stat.FSyncwrites + stat.FAsyncwrites,
diff --git a/disk_freebsd_amd64.go b/disk/disk_freebsd_amd64.go
similarity index 100%
rename from disk_freebsd_amd64.go
rename to disk/disk_freebsd_amd64.go
diff --git a/disk_linux.go b/disk/disk_linux.go
similarity index 100%
rename from disk_linux.go
rename to disk/disk_linux.go
diff --git a/disk_test.go b/disk/disk_test.go
similarity index 100%
rename from disk_test.go
rename to disk/disk_test.go
diff --git a/disk_unix.go b/disk/disk_unix.go
similarity index 100%
rename from disk_unix.go
rename to disk/disk_unix.go
diff --git a/disk_windows.go b/disk/disk_windows.go
similarity index 97%
rename from disk_windows.go
rename to disk/disk_windows.go
index e8bf318..cf8b2e2 100644
--- a/disk_windows.go
+++ b/disk/disk_windows.go
@@ -6,6 +6,8 @@ import (
 	"bytes"
 	"syscall"
 	"unsafe"
+
+	common "github.com/shirou/gopsutil/common"
 )
 
 var (
@@ -113,5 +115,5 @@ func DiskPartitions(all bool) ([]DiskPartitionStat, error) {
 
 func DiskIOCounters() (map[string]DiskIOCountersStat, error) {
 	ret := make(map[string]DiskIOCountersStat, 0)
-	return ret, NotImplementedError
+	return ret, common.NotImplementedError
 }
diff --git a/docker_linux.go b/docker/docker_linux.go
similarity index 100%
rename from docker_linux.go
rename to docker/docker_linux.go
diff --git a/docker_linux_test.go b/docker/docker_linux_test.go
similarity index 100%
rename from docker_linux_test.go
rename to docker/docker_linux_test.go
diff --git a/host.go b/host/host.go
similarity index 100%
rename from host.go
rename to host/host.go
diff --git a/host_darwin.go b/host/host_darwin.go
similarity index 91%
rename from host_darwin.go
rename to host/host_darwin.go
index c666dea..ff9866e 100644
--- a/host_darwin.go
+++ b/host/host_darwin.go
@@ -12,6 +12,8 @@ import (
 	"strconv"
 	"strings"
 	"unsafe"
+
+	common "github.com/shirou/gopsutil/common"
 )
 
 const (
@@ -56,7 +58,7 @@ func HostInfo() (*HostInfoStat, error) {
 		ret.VirtualizationRole = role
 	}
 
-	values, err := doSysctrl("kern.boottime")
+	values, err := common.DoSysctrl("kern.boottime")
 	if err == nil {
 		// ex: { sec = 1392261637, usec = 627534 } Thu Feb 13 12:20:37 2014
 		v := strings.Replace(values[2], ",", "", 1)
@@ -71,7 +73,7 @@ func HostInfo() (*HostInfoStat, error) {
 }
 
 func BootTime() (int64, error) {
-	values, err := doSysctrl("kern.boottime")
+	values, err := common.DoSysctrl("kern.boottime")
 	if err != nil {
 		return 0, err
 	}
@@ -114,9 +116,9 @@ func Users() ([]UserStat, error) {
 			continue
 		}
 		user := UserStat{
-			User: byteToString(u.UtUser[:]),
-			//			Terminal: byteToString(u.UtLine[:]),
-			Host: byteToString(u.UtHost[:]),
+			User: common.ByteToString(u.UtUser[:]),
+			//			Terminal: ByteToString(u.UtLine[:]),
+			Host: common.ByteToString(u.UtHost[:]),
 			//			Started:  int(u.UtTime),
 		}
 		ret = append(ret, user)
diff --git a/host_freebsd.go b/host/host_freebsd.go
similarity index 89%
rename from host_freebsd.go
rename to host/host_freebsd.go
index 71f2d5f..6c3697d 100644
--- a/host_freebsd.go
+++ b/host/host_freebsd.go
@@ -12,6 +12,8 @@ import (
 	"strconv"
 	"strings"
 	"unsafe"
+
+	common "github.com/shirou/gopsutil/common"
 )
 
 func HostInfo() (*HostInfoStat, error) {
@@ -38,7 +40,7 @@ func HostInfo() (*HostInfoStat, error) {
 		ret.VirtualizationRole = role
 	}
 
-	values, err := doSysctrl("kern.boottime")
+	values, err := common.DoSysctrl("kern.boottime")
 	if err == nil {
 		// ex: { sec = 1392261637, usec = 627534 } Thu Feb 13 12:20:37 2014
 		v := strings.Replace(values[2], ",", "", 1)
@@ -53,7 +55,7 @@ func HostInfo() (*HostInfoStat, error) {
 }
 
 func BootTime() (int64, error) {
-	values, err := doSysctrl("kern.boottime")
+	values, err := common.DoSysctrl("kern.boottime")
 	if err != nil {
 		return 0, err
 	}
@@ -96,9 +98,9 @@ func Users() ([]UserStat, error) {
 			continue
 		}
 		user := UserStat{
-			User:     byteToString(u.UtName[:]),
-			Terminal: byteToString(u.UtLine[:]),
-			Host:     byteToString(u.UtHost[:]),
+			User:     common.ByteToString(u.UtName[:]),
+			Terminal: common.ByteToString(u.UtLine[:]),
+			Host:     common.ByteToString(u.UtHost[:]),
 			Started:  int(u.UtTime),
 		}
 		ret = append(ret, user)
diff --git a/host_freebsd_amd64.go b/host/host_freebsd_amd64.go
similarity index 100%
rename from host_freebsd_amd64.go
rename to host/host_freebsd_amd64.go
diff --git a/host_linux.go b/host/host_linux.go
similarity index 97%
rename from host_linux.go
rename to host/host_linux.go
index 71d68f2..d5a5936 100644
--- a/host_linux.go
+++ b/host/host_linux.go
@@ -13,6 +13,8 @@ import (
 	"strings"
 	"syscall"
 	"unsafe"
+
+	common "github.com/shirou/gopsutil/common"
 )
 
 type LSB struct {
@@ -89,9 +91,9 @@ func Users() ([]UserStat, error) {
 			continue
 		}
 		user := UserStat{
-			User:     byteToString(u.UtUser[:]),
-			Terminal: byteToString(u.UtLine[:]),
-			Host:     byteToString(u.UtHost[:]),
+			User:     common.ByteToString(u.UtUser[:]),
+			Terminal: common.ByteToString(u.UtLine[:]),
+			Host:     common.ByteToString(u.UtHost[:]),
 			Started:  int(u.UtTv.TvSec),
 		}
 		ret = append(ret, user)
diff --git a/host_linux_amd64.go b/host/host_linux_amd64.go
similarity index 100%
rename from host_linux_amd64.go
rename to host/host_linux_amd64.go
diff --git a/host_linux_arm.go b/host/host_linux_arm.go
similarity index 100%
rename from host_linux_arm.go
rename to host/host_linux_arm.go
diff --git a/host_linux_test.go b/host/host_linux_test.go
similarity index 100%
rename from host_linux_test.go
rename to host/host_linux_test.go
diff --git a/host_test.go b/host/host_test.go
similarity index 100%
rename from host_test.go
rename to host/host_test.go
diff --git a/host_windows.go b/host/host_windows.go
similarity index 100%
rename from host_windows.go
rename to host/host_windows.go
diff --git a/load.go b/load/load.go
similarity index 100%
rename from load.go
rename to load/load.go
diff --git a/load_darwin.go b/load/load_darwin.go
similarity index 85%
rename from load_darwin.go
rename to load/load_darwin.go
index 0d801d5..6954f0d 100644
--- a/load_darwin.go
+++ b/load/load_darwin.go
@@ -4,10 +4,12 @@ package gopsutil
 
 import (
 	"strconv"
+
+	common "github.com/shirou/gopsutil/common"
 )
 
 func LoadAvg() (*LoadAvgStat, error) {
-	values, err := doSysctrl("vm.loadavg")
+	values, err := common.DoSysctrl("vm.loadavg")
 	if err != nil {
 		return nil, err
 	}
diff --git a/load_freebsd.go b/load/load_freebsd.go
similarity index 85%
rename from load_freebsd.go
rename to load/load_freebsd.go
index c021a30..50196f6 100644
--- a/load_freebsd.go
+++ b/load/load_freebsd.go
@@ -4,10 +4,12 @@ package gopsutil
 
 import (
 	"strconv"
+
+	common "github.com/shirou/gopsutil/common"
 )
 
 func LoadAvg() (*LoadAvgStat, error) {
-	values, err := doSysctrl("vm.loadavg")
+	values, err := common.DoSysctrl("vm.loadavg")
 	if err != nil {
 		return nil, err
 	}
diff --git a/load_linux.go b/load/load_linux.go
similarity index 100%
rename from load_linux.go
rename to load/load_linux.go
diff --git a/load_test.go b/load/load_test.go
similarity index 100%
rename from load_test.go
rename to load/load_test.go
diff --git a/load_windows.go b/load/load_windows.go
similarity index 51%
rename from load_windows.go
rename to load/load_windows.go
index 4d15220..75f07ac 100644
--- a/load_windows.go
+++ b/load/load_windows.go
@@ -2,8 +2,12 @@
 
 package gopsutil
 
+import (
+	common "github.com/shirou/gopsutil/common"
+)
+
 func LoadAvg() (*LoadAvgStat, error) {
 	ret := LoadAvgStat{}
 
-	return &ret, NotImplementedError
+	return &ret, common.NotImplementedError
 }
diff --git a/mem.go b/mem/mem.go
similarity index 100%
rename from mem.go
rename to mem/mem.go
diff --git a/mem_darwin.go b/mem/mem_darwin.go
similarity index 90%
rename from mem_darwin.go
rename to mem/mem_darwin.go
index afeea81..f6282e2 100644
--- a/mem_darwin.go
+++ b/mem/mem_darwin.go
@@ -6,6 +6,8 @@ import (
 	"os/exec"
 	"strconv"
 	"strings"
+
+	common "github.com/shirou/gopsutil/common"
 )
 
 func getPageSize() (uint64, error) {
@@ -29,11 +31,11 @@ func VirtualMemory() (*VirtualMemoryStat, error) {
 		return nil, err
 	}
 
-	total, err := doSysctrl("hw.memsize")
+	total, err := common.DoSysctrl("hw.memsize")
 	if err != nil {
 		return nil, err
 	}
-	free, err := doSysctrl("vm.page_free_count")
+	free, err := common.DoSysctrl("vm.page_free_count")
 	if err != nil {
 		return nil, err
 	}
@@ -68,7 +70,7 @@ func VirtualMemory() (*VirtualMemoryStat, error) {
 func SwapMemory() (*SwapMemoryStat, error) {
 	var ret *SwapMemoryStat
 
-	swapUsage, err := doSysctrl("vm.swapusage")
+	swapUsage, err := common.DoSysctrl("vm.swapusage")
 	if err != nil {
 		return ret, err
 	}
diff --git a/mem_freebsd.go b/mem/mem_freebsd.go
similarity index 80%
rename from mem_freebsd.go
rename to mem/mem_freebsd.go
index 4f70ec4..97dce78 100644
--- a/mem_freebsd.go
+++ b/mem/mem_freebsd.go
@@ -6,10 +6,12 @@ import (
 	"os/exec"
 	"strconv"
 	"strings"
+
+	common "github.com/shirou/gopsutil/common"
 )
 
 func VirtualMemory() (*VirtualMemoryStat, error) {
-	pageSize, err := doSysctrl("vm.stats.vm.v_page_size")
+	pageSize, err := common.DoSysctrl("vm.stats.vm.v_page_size")
 	if err != nil {
 		return nil, err
 	}
@@ -18,31 +20,31 @@ func VirtualMemory() (*VirtualMemoryStat, error) {
 		return nil, err
 	}
 
-	pageCount, err := doSysctrl("vm.stats.vm.v_page_count")
+	pageCount, err := common.DoSysctrl("vm.stats.vm.v_page_count")
 	if err != nil {
 		return nil, err
 	}
-	free, err := doSysctrl("vm.stats.vm.v_free_count")
+	free, err := common.DoSysctrl("vm.stats.vm.v_free_count")
 	if err != nil {
 		return nil, err
 	}
-	active, err := doSysctrl("vm.stats.vm.v_active_count")
+	active, err := common.DoSysctrl("vm.stats.vm.v_active_count")
 	if err != nil {
 		return nil, err
 	}
-	inactive, err := doSysctrl("vm.stats.vm.v_inactive_count")
+	inactive, err := common.DoSysctrl("vm.stats.vm.v_inactive_count")
 	if err != nil {
 		return nil, err
 	}
-	cache, err := doSysctrl("vm.stats.vm.v_cache_count")
+	cache, err := common.DoSysctrl("vm.stats.vm.v_cache_count")
 	if err != nil {
 		return nil, err
 	}
-	buffer, err := doSysctrl("vfs.bufspace")
+	buffer, err := common.DoSysctrl("vfs.bufspace")
 	if err != nil {
 		return nil, err
 	}
-	wired, err := doSysctrl("vm.stats.vm.v_wire_count")
+	wired, err := common.DoSysctrl("vm.stats.vm.v_wire_count")
 	if err != nil {
 		return nil, err
 	}
diff --git a/mem_linux.go b/mem/mem_linux.go
similarity index 100%
rename from mem_linux.go
rename to mem/mem_linux.go
diff --git a/mem_test.go b/mem/mem_test.go
similarity index 100%
rename from mem_test.go
rename to mem/mem_test.go
diff --git a/mem_windows.go b/mem/mem_windows.go
similarity index 100%
rename from mem_windows.go
rename to mem/mem_windows.go
diff --git a/net.go b/net/net.go
similarity index 100%
rename from net.go
rename to net/net.go
diff --git a/net_darwin.go b/net/net_darwin.go
similarity index 100%
rename from net_darwin.go
rename to net/net_darwin.go
diff --git a/net_freebsd.go b/net/net_freebsd.go
similarity index 100%
rename from net_freebsd.go
rename to net/net_freebsd.go
diff --git a/net_linux.go b/net/net_linux.go
similarity index 100%
rename from net_linux.go
rename to net/net_linux.go
diff --git a/net_test.go b/net/net_test.go
similarity index 100%
rename from net_test.go
rename to net/net_test.go
diff --git a/net_windows.go b/net/net_windows.go
similarity index 96%
rename from net_windows.go
rename to net/net_windows.go
index 7a72713..918f4da 100644
--- a/net_windows.go
+++ b/net/net_windows.go
@@ -7,6 +7,8 @@ import (
 	"os"
 	"syscall"
 	"unsafe"
+
+	common "github.com/shirou/gopsutil/common"
 )
 
 var (
@@ -71,7 +73,7 @@ func NetIOCounters(pernic bool) ([]NetIOCountersStat, error) {
 func NetConnections(kind string) ([]NetConnectionStat, error) {
 	var ret []NetConnectionStat
 
-	return ret, NotImplementedError
+	return ret, common.NotImplementedError
 }
 
 // borrowed from src/pkg/net/interface_windows.go
diff --git a/process.go b/process/process.go
similarity index 100%
rename from process.go
rename to process/process.go
diff --git a/process_darwin.go b/process/process_darwin.go
similarity index 81%
rename from process_darwin.go
rename to process/process_darwin.go
index 5e1299f..ab64886 100644
--- a/process_darwin.go
+++ b/process/process_darwin.go
@@ -7,6 +7,10 @@ import (
 	"encoding/binary"
 	"syscall"
 	"unsafe"
+
+	common "github.com/shirou/gopsutil/common"
+	cpu "github.com/shirou/gopsutil/cpu"
+	net "github.com/shirou/gopsutil/net"
 )
 
 // MemoryInfoExStat is different between OSes
@@ -31,7 +35,7 @@ func Pids() ([]int32, error) {
 }
 
 func (p *Process) Ppid() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 
 	k, err := p.getKProc()
 	if err != nil {
@@ -49,19 +53,19 @@ func (p *Process) Name() (string, error) {
 	return string(k.KiComm[:]), nil
 }
 func (p *Process) Exe() (string, error) {
-	return "", NotImplementedError
+	return "", common.NotImplementedError
 }
 func (p *Process) Cmdline() (string, error) {
-	return "", NotImplementedError
+	return "", common.NotImplementedError
 }
 func (p *Process) CreateTime() (int64, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) Cwd() (string, error) {
-	return "", NotImplementedError
+	return "", common.NotImplementedError
 }
 func (p *Process) Parent() (*Process, error) {
-	return p, NotImplementedError
+	return p, common.NotImplementedError
 }
 func (p *Process) Status() (string, error) {
 	k, err := p.getKProc()
@@ -110,23 +114,23 @@ func (p *Process) Terminal() (string, error) {
 	return termmap[ttyNr], nil
 }
 func (p *Process) Nice() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) IOnice() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) Rlimit() ([]RlimitStat, error) {
 	var rlimit []RlimitStat
-	return rlimit, NotImplementedError
+	return rlimit, common.NotImplementedError
 }
 func (p *Process) IOCounters() (*IOCountersStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) NumCtxSwitches() (*NumCtxSwitchesStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) NumFDs() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) NumThreads() (int32, error) {
 	k, err := p.getKProc()
@@ -138,16 +142,16 @@ func (p *Process) NumThreads() (int32, error) {
 }
 func (p *Process) Threads() (map[string]string, error) {
 	ret := make(map[string]string, 0)
-	return ret, NotImplementedError
+	return ret, common.NotImplementedError
 }
-func (p *Process) CPUTimes() (*CPUTimesStat, error) {
-	return nil, NotImplementedError
+func (p *Process) CPUTimes() (*cpu.CPUTimesStat, error) {
+	return nil, common.NotImplementedError
 }
 func (p *Process) CPUPercent() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) CPUAffinity() ([]int32, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) MemoryInfo() (*MemoryInfoStat, error) {
 	k, err := p.getKProc()
@@ -163,30 +167,30 @@ func (p *Process) MemoryInfo() (*MemoryInfoStat, error) {
 	return ret, nil
 }
 func (p *Process) MemoryInfoEx() (*MemoryInfoExStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) MemoryPercent() (float32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 
 func (p *Process) Children() ([]*Process, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 
 func (p *Process) OpenFiles() ([]OpenFilesStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 
-func (p *Process) Connections() ([]NetConnectionStat, error) {
-	return nil, NotImplementedError
+func (p *Process) Connections() ([]net.NetConnectionStat, error) {
+	return nil, common.NotImplementedError
 }
 
 func (p *Process) IsRunning() (bool, error) {
-	return true, NotImplementedError
+	return true, common.NotImplementedError
 }
 func (p *Process) MemoryMaps(grouped bool) (*[]MemoryMapsStat, error) {
 	var ret []MemoryMapsStat
-	return &ret, NotImplementedError
+	return &ret, common.NotImplementedError
 }
 
 func copyParams(k *KinfoProc, p *Process) error {
diff --git a/process_darwin_amd64.go b/process/process_darwin_amd64.go
similarity index 100%
rename from process_darwin_amd64.go
rename to process/process_darwin_amd64.go
diff --git a/process_freebsd.go b/process/process_freebsd.go
similarity index 82%
rename from process_freebsd.go
rename to process/process_freebsd.go
index 101b3fc..95f76c7 100644
--- a/process_freebsd.go
+++ b/process/process_freebsd.go
@@ -7,6 +7,10 @@ import (
 	"encoding/binary"
 	"syscall"
 	"unsafe"
+
+	common "github.com/shirou/gopsutil/common"
+	cpu "github.com/shirou/gopsutil/cpu"
+	net "github.com/shirou/gopsutil/net"
 )
 
 // MemoryInfoExStat is different between OSes
@@ -47,19 +51,19 @@ func (p *Process) Name() (string, error) {
 	return string(k.KiComm[:]), nil
 }
 func (p *Process) Exe() (string, error) {
-	return "", NotImplementedError
+	return "", common.NotImplementedError
 }
 func (p *Process) Cmdline() (string, error) {
-	return "", NotImplementedError
+	return "", common.NotImplementedError
 }
 func (p *Process) CreateTime() (int64, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) Cwd() (string, error) {
-	return "", NotImplementedError
+	return "", common.NotImplementedError
 }
 func (p *Process) Parent() (*Process, error) {
-	return p, NotImplementedError
+	return p, common.NotImplementedError
 }
 func (p *Process) Status() (string, error) {
 	k, err := p.getKProc()
@@ -108,23 +112,23 @@ func (p *Process) Terminal() (string, error) {
 	return termmap[ttyNr], nil
 }
 func (p *Process) Nice() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) IOnice() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) Rlimit() ([]RlimitStat, error) {
 	var rlimit []RlimitStat
-	return rlimit, NotImplementedError
+	return rlimit, common.NotImplementedError
 }
 func (p *Process) IOCounters() (*IOCountersStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) NumCtxSwitches() (*NumCtxSwitchesStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) NumFDs() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) NumThreads() (int32, error) {
 	k, err := p.getKProc()
@@ -136,16 +140,16 @@ func (p *Process) NumThreads() (int32, error) {
 }
 func (p *Process) Threads() (map[string]string, error) {
 	ret := make(map[string]string, 0)
-	return ret, NotImplementedError
+	return ret, common.NotImplementedError
 }
-func (p *Process) CPUTimes() (*CPUTimesStat, error) {
-	return nil, NotImplementedError
+func (p *Process) CPUTimes() (*cpu.CPUTimesStat, error) {
+	return nil, common.NotImplementedError
 }
 func (p *Process) CPUPercent() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) CPUAffinity() ([]int32, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) MemoryInfo() (*MemoryInfoStat, error) {
 	k, err := p.getKProc()
@@ -161,30 +165,30 @@ func (p *Process) MemoryInfo() (*MemoryInfoStat, error) {
 	return ret, nil
 }
 func (p *Process) MemoryInfoEx() (*MemoryInfoExStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) MemoryPercent() (float32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 
 func (p *Process) Children() ([]*Process, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 
 func (p *Process) OpenFiles() ([]OpenFilesStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 
-func (p *Process) Connections() ([]NetConnectionStat, error) {
-	return nil, NotImplementedError
+func (p *Process) Connections() ([]net.NetConnectionStat, error) {
+	return nil, common.NotImplementedError
 }
 
 func (p *Process) IsRunning() (bool, error) {
-	return true, NotImplementedError
+	return true, common.NotImplementedError
 }
 func (p *Process) MemoryMaps(grouped bool) (*[]MemoryMapsStat, error) {
 	var ret []MemoryMapsStat
-	return &ret, NotImplementedError
+	return &ret, common.NotImplementedError
 }
 
 func copyParams(k *KinfoProc, p *Process) error {
diff --git a/process_freebsd_amd64.go b/process/process_freebsd_amd64.go
similarity index 100%
rename from process_freebsd_amd64.go
rename to process/process_freebsd_amd64.go
diff --git a/process_linux.go b/process/process_linux.go
similarity index 94%
rename from process_linux.go
rename to process/process_linux.go
index 6460ac6..ede8f3f 100644
--- a/process_linux.go
+++ b/process/process_linux.go
@@ -10,6 +10,10 @@ import (
 	"strconv"
 	"strings"
 	"syscall"
+
+	common "github.com/shirou/gopsutil/common"
+	cpu "github.com/shirou/gopsutil/cpu"
+	net "github.com/shirou/gopsutil/net"
 )
 
 const (
@@ -89,7 +93,7 @@ func (p *Process) Cwd() (string, error) {
 	return p.fillFromCwd()
 }
 func (p *Process) Parent() (*Process, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) Status() (string, error) {
 	return p.status, nil
@@ -115,10 +119,10 @@ func (p *Process) Nice() (int32, error) {
 	return nice, nil
 }
 func (p *Process) IOnice() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) Rlimit() ([]RlimitStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) IOCounters() (*IOCountersStat, error) {
 	return p.fillFromIO()
@@ -127,7 +131,7 @@ func (p *Process) NumCtxSwitches() (*NumCtxSwitchesStat, error) {
 	return p.numCtxSwitches, nil
 }
 func (p *Process) NumFDs() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) NumThreads() (int32, error) {
 	return p.numThreads, nil
@@ -136,7 +140,7 @@ func (p *Process) Threads() (map[string]string, error) {
 	ret := make(map[string]string, 0)
 	return ret, nil
 }
-func (p *Process) CPUTimes() (*CPUTimesStat, error) {
+func (p *Process) CPUTimes() (*cpu.CPUTimesStat, error) {
 	_, _, cpuTimes, _, _, err := p.fillFromStat()
 	if err != nil {
 		return nil, err
@@ -144,10 +148,10 @@ func (p *Process) CPUTimes() (*CPUTimesStat, error) {
 	return cpuTimes, nil
 }
 func (p *Process) CPUPercent() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) CPUAffinity() ([]int32, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) MemoryInfo() (*MemoryInfoStat, error) {
 	return p.memInfo, nil
@@ -160,23 +164,23 @@ func (p *Process) MemoryInfoEx() (*MemoryInfoExStat, error) {
 	return memInfoEx, nil
 }
 func (p *Process) MemoryPercent() (float32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 
 func (p *Process) Children() ([]*Process, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 
 func (p *Process) OpenFiles() ([]OpenFilesStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 
-func (p *Process) Connections() ([]NetConnectionStat, error) {
-	return nil, NotImplementedError
+func (p *Process) Connections() ([]net.NetConnectionStat, error) {
+	return nil, common.NotImplementedError
 }
 
 func (p *Process) IsRunning() (bool, error) {
-	return true, NotImplementedError
+	return true, common.NotImplementedError
 }
 
 // MemoryMaps get memory maps from /proc/(pid)/smaps
@@ -513,7 +517,7 @@ func (p *Process) fillFromStatus() error {
 	return nil
 }
 
-func (p *Process) fillFromStat() (string, int32, *CPUTimesStat, int64, int32, error) {
+func (p *Process) fillFromStat() (string, int32, *cpu.CPUTimesStat, int64, int32, error) {
 	pid := p.Pid
 	statPath := filepath.Join("/", "proc", strconv.Itoa(int(pid)), "stat")
 	contents, err := ioutil.ReadFile(statPath)
@@ -545,7 +549,7 @@ func (p *Process) fillFromStat() (string, int32, *CPUTimesStat, int64, int32, er
 		return "", 0, nil, 0, 0, err
 	}
 
-	cpuTimes := &CPUTimesStat{
+	cpuTimes := &cpu.CPUTimesStat{
 		CPU:    "cpu",
 		User:   float32(utime * (1000 / ClockTicks)),
 		System: float32(stime * (1000 / ClockTicks)),
diff --git a/process_linux_amd64.go b/process/process_linux_amd64.go
similarity index 100%
rename from process_linux_amd64.go
rename to process/process_linux_amd64.go
diff --git a/process_linux_arm.go b/process/process_linux_arm.go
similarity index 100%
rename from process_linux_arm.go
rename to process/process_linux_arm.go
diff --git a/process_posix.go b/process/process_posix.go
similarity index 100%
rename from process_posix.go
rename to process/process_posix.go
diff --git a/process_posix_test.go b/process/process_posix_test.go
similarity index 100%
rename from process_posix_test.go
rename to process/process_posix_test.go
diff --git a/process_test.go b/process/process_test.go
similarity index 100%
rename from process_test.go
rename to process/process_test.go
diff --git a/process_windows.go b/process/process_windows.go
similarity index 79%
rename from process_windows.go
rename to process/process_windows.go
index 0f95984..7424f81 100644
--- a/process_windows.go
+++ b/process/process_windows.go
@@ -8,6 +8,8 @@ import (
 	"unsafe"
 
 	"github.com/shirou/w32"
+
+	common "github.com/shirou/gopsutil/common"
 )
 
 const (
@@ -61,7 +63,7 @@ func (p *Process) Ppid() (int32, error) {
 }
 func (p *Process) Name() (string, error) {
 	name := ""
-	return name, NotImplementedError
+	return name, common.NotImplementedError
 }
 func (p *Process) Exe() (string, error) {
 	_, _, ret, err := p.getFromSnapProcess(p.Pid)
@@ -71,51 +73,51 @@ func (p *Process) Exe() (string, error) {
 	return ret, nil
 }
 func (p *Process) Cmdline() (string, error) {
-	return "", NotImplementedError
+	return "", common.NotImplementedError
 }
 func (p *Process) Cwd() (string, error) {
-	return "", NotImplementedError
+	return "", common.NotImplementedError
 }
 func (p *Process) Parent() (*Process, error) {
-	return p, NotImplementedError
+	return p, common.NotImplementedError
 }
 func (p *Process) Status() (string, error) {
-	return "", NotImplementedError
+	return "", common.NotImplementedError
 }
 func (p *Process) Username() (string, error) {
-	return "", NotImplementedError
+	return "", common.NotImplementedError
 }
 func (p *Process) Uids() ([]int32, error) {
 	var uids []int32
 
-	return uids, NotImplementedError
+	return uids, common.NotImplementedError
 }
 func (p *Process) Gids() ([]int32, error) {
 	var gids []int32
-	return gids, NotImplementedError
+	return gids, common.NotImplementedError
 }
 func (p *Process) Terminal() (string, error) {
-	return "", NotImplementedError
+	return "", common.NotImplementedError
 }
 func (p *Process) Nice() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) IOnice() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) Rlimit() ([]RlimitStat, error) {
 	var rlimit []RlimitStat
 
-	return rlimit, NotImplementedError
+	return rlimit, common.NotImplementedError
 }
 func (p *Process) IOCounters() (*IOCountersStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) NumCtxSwitches() (*NumCtxSwitchesStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) NumFDs() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) NumThreads() (int32, error) {
 	_, ret, _, err := p.getFromSnapProcess(p.Pid)
@@ -126,46 +128,46 @@ func (p *Process) NumThreads() (int32, error) {
 }
 func (p *Process) Threads() (map[string]string, error) {
 	ret := make(map[string]string, 0)
-	return ret, NotImplementedError
+	return ret, common.NotImplementedError
 }
 func (p *Process) CPUTimes() (*CPUTimesStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) CPUPercent() (int32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 func (p *Process) CPUAffinity() ([]int32, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) MemoryInfo() (*MemoryInfoStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) MemoryInfoEx() (*MemoryInfoExStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 func (p *Process) MemoryPercent() (float32, error) {
-	return 0, NotImplementedError
+	return 0, common.NotImplementedError
 }
 
 func (p *Process) Children() ([]*Process, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 
 func (p *Process) OpenFiles() ([]OpenFilesStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 
 func (p *Process) Connections() ([]NetConnectionStat, error) {
-	return nil, NotImplementedError
+	return nil, common.NotImplementedError
 }
 
 func (p *Process) IsRunning() (bool, error) {
-	return true, NotImplementedError
+	return true, common.NotImplementedError
 }
 
 func (p *Process) MemoryMaps(grouped bool) (*[]MemoryMapsStat, error) {
 	ret := make([]MemoryMapsStat, 0)
-	return &ret, NotImplementedError
+	return &ret, common.NotImplementedError
 }
 
 func NewProcess(pid int32) (*Process, error) {
@@ -175,20 +177,20 @@ func NewProcess(pid int32) (*Process, error) {
 }
 
 func (p *Process) SendSignal(sig syscall.Signal) error {
-	return NotImplementedError
+	return common.NotImplementedError
 }
 
 func (p *Process) Suspend() error {
-	return NotImplementedError
+	return common.NotImplementedError
 }
 func (p *Process) Resume() error {
-	return NotImplementedError
+	return common.NotImplementedError
 }
 func (p *Process) Terminate() error {
-	return NotImplementedError
+	return common.NotImplementedError
 }
 func (p *Process) Kill() error {
-	return NotImplementedError
+	return common.NotImplementedError
 }
 
 func (p *Process) getFromSnapProcess(pid int32) (int32, int32, string, error) {