WideStudio is an Integrated Development Environment (IDE) for building window applications in C++, Ruby, Python an Perl for Windows, MacOSX, Linux, FreeBSD, SOLARIS and other unix and BTRON and T-Engine. This is open and free (under MIT/X Consortiun Lice
Raddle is a network emulation framework. It is particularly useful when testing network management systems or teaching people to use them. Raddle supports ping, SNMP, traceroute, and other protocols.