MakeNG is a system of makefiles that, in conjuncture with a patch to GNU Make, provides a concise, extensible, logically organized and easily modified system of makefiles to build any source tree or combination of components you can envision. MakeNG sports a fully documented extensible API on top of the classic GNU Make syntax (which is great for backwards compatibility).
OzVM (Virtual Machine Project) is a simple, lightweight, secure virtual machine. The current target application of OzVM is OzStream, which allows platform independent self-decoding of data. The vision of OzStream is to make any and all compressed media self-extracting. OzStream abstracts compressed media from client applications, providing new freedom for users, developers, and compression techniques.
Over5 is a program for transferring between c64/vic20 machines and Amiga/PC/UNIX boxes. It supports serial transfer at 38400 bps using only a RS-232 level converter and a 3-line standard nullmodem cable. No special serialport chips are needed. Source code is included. It features read/write/execute memory, filecopy with wildcards, read/write raw disk, read/write ZIPCODE archive, the ability to use the Amiga/PC/UNIX box as a harddisk server ($0801-$f600), builtin diskturbo, and a fast basic bootstrap for most cbm 8-bitters.