If there's one thing you've probably noticed with Deniska's recent works, it's about porting old-school games over to the PSP. This time around,  the dev's created something meant for fellow coders out there with the release of sdlBasic 05. 

As its name implies, it's a PSP port of the multiplatform interpreter for BASIC (Beginner's All-purpose Symbolic Instruction Code). It's built to make use of the SDL library for creating games. SdlBasic was originally created by Vroby (Roberto Viola) back in 2002. As for the features found in Deniska's port (quoting the readme):

• setdisplay() dimensions are limited to 640x480, 320x240, 480x272 (and some derivatives)
• only some keyboard keys are mapped (arrows, enter, space, escape) and available through key() / inkey commands.
• all psp buttons can be queried with getButtonJoystick() call with button indexes from 0 to 13
• mouse calls are partially implemented via the analog pad and buttons mapped to [x],[o],[triangle],[square]
• isPSP=1 and os=PSP variables are added for platform detection.
• network, mpeg and cd-control calls as well as shell() are not implemented yet.
• mp3 playbeack is not supported. Ogg, wav and tracker formats should be used instead.
  

Deniska further notes that sdlBasic will only work on PSPs with Custom Firmware 3.xx. Further details on this dev library are available in the readme included in the file bundle.

Download: sdlBasic v 0.5