In response to customer demands (and many long discussions on the REALBasic mailing list), REAL Software has announced that RB 5.5 will be capable of cross-compiling apps for Red Hat and SuSE distributions of Linux, with other distros being added according to demand. You'll still need either a Mac or Windows box to create and cross-compile the app for Linux. You'll have to wait for the Linux-based REALBasic IDE, but REAL Software says that they intend to make one available in a later version.

RB 5.5 is expected to be released in the first quarter of 2004.