Thank you for accepting my registration to AllBasic forum.
That's a good question.
JustBasic - good for testing bits of code and ideas
YaBasic - also good for testing bits of code and ideas
FreeBasic - can compile qbasic programs without the same memory limits and on newer machines
Variants of GFA Basic - classic languages with several variants
IWBasic - contains important updates to the IBasic and EBasic legacy
I can hardly name five as newer software often doesn't suit my preferences.
I would also like to mention Blitz Basic and Emergence Basic as they are important to me, but not quite available or supported.
HobbyBasic from FASMforum deserves a very honorable mention. It's tiny, fast, and powerful
OxygenBasic looks amazing an I am looking towards trying it out.