ImprovLA is a popular, workshop on long form improvisation founded by longtime improviser, actor, and comedian Keith Saltojanes, based in Los Angeles.
From the ImprovLA website:
Improv-LA is a place for improvisers, actors, and non-actors to come together to learn and strengthen their talent as a performer by focusing on the skills of long form improvisation. Whether you have no prior experience in improv or just want to get better, Improv-LA can help you.
Taught by veteran improviser and actor, Keith Saltojanes, has taken the concepts off all of his experience and training in both improvisation and acting and streamlined it into a workshop that can be the most beneficial for everyone involved.
The workshop is designed as a drop-in class, meaning it has no linear curriculum; you can show up any week and jump right in, or attend consecutive weeks and learn even more. Each class focuses on a different skill to make you better, smarter, stronger, and more confident at improvising in the moment.
ImprovLA also hosts a bi-weekly podcast on learning long form improvisation.