Despite having recently lost its CFO, travel search company KAYAK is reported to be kicking off an IPO roadshow as soon as next week, a year and a half after initially filing to go public. Boston will be paying close attention whenever KAYAK finally does go public, in part because the city has a growing cluster of travel related startups.

In addition to KAYAK there is, of course, TripAdvisor in Newton, which went public at the end of last year, and ITA which was acquired by Google in April 2011. But beyond these established players, there are several promising startups here as well, one of which even moved to Boston after receiving funding.

Here are seven travel companies – big and small – in and around Boston that you should know:

(Hipmunk, by the way, was started by an MIT grad, though it’s San Francisco based.) What explains Boston’s strength in this area?