HelenOS sources

root/uspace/lib/

[..]
ata/ bithenge/ block/ c/ clipboard/
clui/ codepage/ compress/ congfx/ console/
corecfg/ cpp/ crypto/ ddev/ device/
dispcfg/ display/ dltest/ drv/ ext4/
fbfont/ fdisk/ fmgt/ fmtutil/ fs/
futil/ gfx/ gfxfont/ gfximage/ hound/
http/ ieee80211/ inet/ input/ ipcgfx/
ipctest/ label/ math/ memgfx/ minix/
nettl/ nic/ ofw/ output/ pcm/
pcut/ pixconv/ posix/ riff/ scsi/
sif/ system/ tbarcfg/ termui/ trackmod/
ui/ untar/ uri/ usb/ usbdev/
usbhid/ usbhost/ usbvirt/ virtio/ vt/
wndmgt/
[..]
HelenOS homepage, sources at GitHub