what do you mean by a custom OS? Anything that isn't windows? If yes, then yes, there are alot of decent 'custom' OSes out there, you should try looking through the different linux distributions if you're curious. I use ubuntu.
tinyxp and tinyvista are stripped down versions of XP and vista respectively. They take up much less disk space and run much faster, but in trade off do not have all the capabilities of the full OSes (I seem to remember tinyxp can't run microsoft office or directx). Stock 2003 is windows 2003 as microsoft supply it, i.e unmodified.
Well... I though stock was part of the name. I can deal with tinyxp on my parents old comp, but I kinda need office and directx.
Heard it has malware... Is there ANY x64 bit versions of TinyXP/TinyVista/Tiny7? I DONT want to use my old computer...