Introducing wxBasic
wxb is a cross-platform BASIC interpreter licensed under the LGPL. While not complying with the ANSI BASIC standard, wxBasic provides much of the functionality associated with modern structured BASIC, along with a number of extentions borrowed from languages such as Python, Lua and Java.
At its core, wxBasic is a fairly small language, weighing in at under 300K (less than 80K when compressed via UPX). However, wxBasic gains much of its functionality by using the wxWidgets library, which provides a cross-platform GUI and non-GUI functionality. The wxWidgets-enabled version of wxBasic is far more capable, but quite a bit heftier.