From Sonic Retro
Sega Retro is a wiki and sister-site to Sonic Retro. It was created due to the large influx of Sega-related articles on Sonic Retro - the idea being that Sonic content would solely be on its own wiki, with Sega content being on a new wiki. Sega Retro aims to cover everything related to Sega, whether that be games, albums, people, corporate structure or any product the company has released since 1945.
Sega Retro was launched on April 1, 2010, earlier than expected, as part of an April Fools prank, when it was announced that all Sonic content would be removed from the entire website, instead focusing on Sega instead. Even though that the removal of Sonic content was a joke, most of the memberbase supported this new wiki.
Any Sega content that was originally on Sonic Retro is now on Sega Retro, with redirects leading to the new pages. Similarly, any Sonic content linked on Sega Retro is redirected to Sonic Retro.
In early 2012 Sega Retro officially overtook Sonic Retro in terms of size - as of February 2012 Sega Retro contains over 4500 articles and is rapidly growing, while Sonic Retro is just shy of 4300.
On April 1, 2013 it was announced that SEGAbits would partner with Sonic Retro and would integrate Sega Retro intro the existing SEGAbits site.