BOOM is often short for Boomerang - where each participant sends in enough fat 8ths for each to the host, then the host sorts and sends everyone back a set of different fat 8ths, We make blocks and when complete, send them back to the host and she resorts and sends back to each participant, so in the end you get a set of blocks made using the fabric you picked. Janice McC has hosted several of them over the years.
recent BOOM thread