asmutils is a set of miscellaneous utilities written in assembly language, targeted on embedded systems and small distributions (e.g. installation or rescue disks). It also contains a small libc and a crypto library. It is optimized for size, memory usage, and speed, and offers fairly good functionality. The project supports Linux and the BSD family. Unixware, Solaris, and AtheOS support is in beta stage. This package also aims to provide a portable development framework, and to encourage assembly programmers to write for Linux/Unix.
BeeCrypt is an ongoing project to provide strong and fast cryptography in the form of a toolkit usable by commercial and open source projects. Included in the library are entropy sources, random generators, block ciphers, hash functions, message authentication codes, multiprecision integer routines, and public key primitives.
diet libc contains the system call wrappers and the most commonly-used functions you expect from a libc. It can be used to create small, statically-linked binaries under x86, AMD64, SPARC, SPARC64, PPC, PPC64, ARM, MIPS, MIPS64, PA-RISC, S/390, S/390x (64-bit S/390), and Alpha-Linux.
e3 is a full-screen, user-friendly text editor with an interface similar to that of either WordStar, Emacs, Pico, Nedit, or vi. It's heavily optimized for size and independent of libc or any other libraries, making it useful for mini-Linux distributions and rescue disks. The assembler version supports Linux, FreeBSD, OpenBSD, NetBSD, Win9x, QNX, Atheos, BeOS, ELKS, and DOS. There is also a separately distributed version written in C which supports some other Unix versions and CygWin. It is also possible to use regular expressions by using child processes like sed. e3 has a built in arithmetic calculator.