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.
Setedit is a text editor specially designed for programmers. It has a nice interface with mouse support, menus and windows (text mode). The editor is a very good choice for people with DOS background, especially people accustomed to Worstar and Borland editors. The editor has overlapped windows so you can see more than one file at the same time, configurable syntax highlighting, macros, rectangular selection, block indentation, as well as customizable keyboard shortcuts and menus.
Vim is an almost fully-compatible version of the Unix editor Vi. Many new features have been added including multi-level undo, syntax highlighting, commandline history, online help, filename completion, and block operations. It is descended from the vi clone "stevie" and runs on many systems, including Unix, MS Windows, OS/2, Macintosh, VMS, and Amiga.
Open Watcom consists of the famous Watcom C++ and WATFOR compilers -- now open source. Open Watcom is mainly used for developing embedded, DOS, and ncurses software. Open Watcom includes the C/C++/Fortran IDE from Watcom for DOS and a full set of command-line tools for compilation, including the superb Watcom debugger. Open Watcom emits easy-to-understand errors and warnings when things go wrong. Open Watcom generates small statically linked binaries for Linux, Win32, Win16, OS/2, QNX, NetWare, and MS-DOS real and protected mode, among other targets. However, Open Watcom is still only beta-quality on Linux and BSD. The two most serious issues are imperfect C++ template support and an inability to dynamically link with shared libraries built by GCC. Also, Open Watcom is released under the Sybase Open Watcom Public License, which is considered non-free by most Debian Linux developers. NOTE: Open Watcom binaries for Linux are not available anywhere. You must build it yourself. 1.5 has known build issues on Linux; use version 1.4 or the current daily build instead.