14 DAY TRIAL // Left 4 Dead 2 has been released by Valve, along with Portal, on Steam for Linux, for some time now, but the developers continue to update it on a regular basis.
Most of the Left 4 Dead 2 updates so far have been released for balancing purposes, but the new one is focused on add-on management.
For example, conflicts between mission scripts in the Add-ons menu are now reported, checked items no longer get unchecked after reporting a conflict, all add-ons are now allowed to override base content at the main menu, content-only add-ons are now allowed on non-vanilla dedicated servers, and add-ons are now allowed to override base missions and mode scripts on non-vanilla servers.
More details about this release can be found in the official announcement. Also, you can check out our review of Left 4 Dead 2.