Omnitographer
Newcomer
Any game set up to allow it can offer access to old versions of their clients via the Beta functionality of steam, with the major impact on mods 1.6 and smapi 4.0 will have it would be great to be able to lock SDV into 1.5 until such time as all the mods players use are updated for 1.6. Factorio for example lets you play a number of older major versions of the game:
