I began learning UNIX in 1979, and had my first access to a real unix system on 1987. My experience spreads almost all known un*x varieties, including:

• Linux
• AIX
• hp-ux
• FreeBSD
• OpenBSD
• NetBSD
• Solaris
• non-stop-ux (TANDEM)
• SysV
• SCO UNIX (from Santa Cruz Operation)

I have developed production drivers in SCO UNIX(several devices, including touchscreen and coin dispensers/aceptors) and Linux(ISDN PCI cards). I have been lecturer for UNIX Operating Systems along all my career since 1987.

Now I'm learning about system internals of FreeBSD system and will teach them if somebody has interest on it.