Wikipedia
XBLite
XBLite is a free Open Source BASIC programming language compiler and development system. It was started in 2001 by David Szafranski in order to provide a Windows exclusive version of the XBasic dialect. XBLite is released under the GNU GPL licensing scheme, Standard libraries are released under the GNU LGPL licensing scheme.
The XBLite syntax is very similar to that of XBasic and somewhat similar to Microsoft's QuickBASIC in that it is a procedural language capable of subs and functions. XBLite also has 64 bit integer data type, User Defined Types and the ability to have multiple modules in order to create GUI applications or games.