flash chip question for EVO

ok well im new to this whole EVO thing and ive mostly delt with early 90's nissans and VW. I have a flash chip for my 20th ae GTI golf which i love. but its a vw specific company, and ive read about EVO's that have similar chips but no name of the companys. my question is, whats the company or companys that offer this? I'm totally clueless when it comes to mitsu....because ive never delt with them so any help or suggestions will be appreciated in the help with my research to get familiarized with this platform. Also if i could get any websites for the major manufactures that offer EVO specific parts would be nice to. I'm sure these are common questions so sorry, I figured this would be a ggod place to start, thanks KeithO.