epsxe is free?

Boys i was tinking, an emulator for dreamcast of EPSXE is possible?
In the home page i see a LINUX version, but i not see the open source, this emu is proibited make why the source not is free?
Thank you.
P.S. excuse me, for me questions, can be stupid, but if i don't speak here, where can answer at my questions. ^__^

generally, if there is a linux build, it is opensource.

EPSXE is a great emulator, but its probably not the most portable. The only homegrown psx emulator for DC is built from PCSX.

I don't understand, explain me, from where understand wich an emu not is portable to the dreamcast?
What is necessary for a good porting? ._.

some things are more portable than others. for instance. snes9x is more portable than ZSNES due to the way it was programmed..