UPS is a source level C, C++ and Fortran debugger with an X windows interface. An ANSI compliant C interpreter is included. Currently supports SunOS on Sun SPARC, and FreeBSD and Linux on Intel x86. Release 3.38-beta2 includes support for the DWARF 2 debugging format used by GCC 3.x, in C and C++ programs only.
http://ups.sourceforge.net/CHANGES lists major changes included in this and previous releases.