The latest version of HPGCC offers many enhancements from earlier versions. Most notably, the compiled code is now in ARM Thumb mode by default, resulting in great reduction in code size with little performance hit. Besides implementing most of ANSI C, there are device-specific libraries that allow access to things like the calculator's RPN stack, memory and piezoelectric buzzer. The GCC compiler itself is the property of the Free Software Foundation, and they state that its use does not impose any particular licensing restrictions on any of its output. However, the libraries included with HPGCC, including routines necessary to actually invoke any HPGCC-compiled program on an actual calculator, are released under a modified GPL license, contrary to GCC on many other platforms which use a more permissive license for their libraries. Thus any programs that link against them can only be distributed if they are also released under the GPL (with an exception for "non-profit" software).