Josh "Cheeseness" Bush, the man behind the recent port of Double Fine's Day of the Tentacle Remastered to Linux, has posted an excellent retrospective on his experience in porting the game. He has also shared the sourcecode of the Coming Soon app that was live on Steam before the Linux port was released.
Be sure to check it out, if you're a fan of Day of the Tentacle (who here isn't?), as it's quite an informative and interesting read.