There are four theaters in Austin, Texas that produce improv shows:
The Merlin Works Institute for Improvisation also teaches classes and produces shows at the ZACH theater.
The Comedy Workshop is the earliest known home to improv in Austin -- they taught weekly improv workshops and hosted the first known Austin improv shows in the early 1980s.
Cafe Caffeine was the home of Austin ComedySportz between 2009 and 2010.
The Highball hosted a number of shows from The Institution Theater between 2009 and 2012.
The Spider House hosted the original run of Staged by the Bell in 2009, and has hosted occasional improv shows since then.
The Lair was an improv theater in Round Rock that opened and closed in 2010.
Prior to 2013, Gnap! Theater Projects produced improv shows at Salvage Vanguard Theater. The theater still hosts occasional improv shows, but is largely inactive.