User:Dozen/E (text editor family)

The E text editor from IBM has been available in various versions, first for DOS in 1984 and later with OS/2 in 1987. E was also ported to AIX, IBM's version of Unix. It has gone by the names E, System Editor, and EPM (E for the Presentation Manager, OS/2). In addition to being a commercial product, E was used in-house by many IBM programmers, and often referred to by version, as E2 or E3. Several non-IBM editors trace their descent from this family as well.

Early History
E was inspired by the Personal Editor (aka pe), a key configurable editor that enabled limited programming using a GML-like language. Personal Editor was initially used internally by IBM in 1982 and became a product not long after. It was authored by Jim Wylie and released under IBM's Personally Developed Software program. Like E, the Personal Editor has often been referred to by its version, as in pe2 and pe3. At least one third party direct descendant is still available in 2007, as Personal Editor 32.

E was a different editor, however. It was designed to fully support the memory available on the Intel 80286, so it did not need to page through large files. It also used a completely different configuration language, providing superior extensibility.

E family
Limitations in Personal Editor led to the development and release in 1984 of the E editor, a much faster editor that supported very long files and included a substantially enhanced user interface. E2, released in 1985, provided enhanced programmability using a REXX-like language. Its UI programmability was designed so flexibly that it was used to develop user interface prototypes for other kinds of software, including Word Processors and Survey software. Subsequent versions, including E3, EOS2, and EPM, provided a wide range of other enhancements. The OS/2 System Editor was developed by the E programming team at the request of the OS/2 Development team. It was designed to be a fast and highly functional text editor with a minimal number of features and no configurability. EPM was later released as the OS/2 Enhanced Editor. The popular SlickEdit shares a common heritage, having been written by the principal original developer of E3. Other versions of E family editors have been released with IBM programming products.

E (PC-DOS)
E is the text editor which was made part of PC-DOS with version 6.1 in June 1993, and later with version 7 and PC-DOS 2000. In version 6.1, IBM dropped Microsoft BASIC, which, in its edit mode, was also the system text editor. It was necessary to provide some sort of editor, so IBM chose to adapt and substantially extend its OS/2 System Editor (1986), a minimally functional member of the E family of Editors. The DOS version is extended with a wide array of functions that are usually associated with more functional versions of the E editor family (see below). In version 7, IBM added the REXX language to DOS, restoring programmability to the basic box. IBM also provided E with OS/2.

E is not an MS-DOS edit clone. Quite the contrary, MS-DOS edit is yet another version of the OS/2 System Editor. It is impossible to know whether Microsoft used the OS/2 System Editor code intact or simply rewrote the program based on the specification, but it remains that the menus and other details of the original editor a virtually identical to that of the original OS/2 System Editor. The DOS version of E is more capable than either Edit or OS/2 System editor, however. Much of the original IBM E Editor's configurability has been restored. The features include (for PC DOS 7):


 * online help
 * edit large text files
 * draw boxes around text
 * mouse and menu support
 * record and play keystroke macros
 * change case within a marked area
 * access multiple files in multiple panes
 * syntax-directed editing of C and REXX
 * add and multiply numbers in a marked area
 * locate and make a change globally within a file
 * select text and move, copy, overlay, or delete it
 * copy and move text from one file into another file

E for PC-DOS consists of four files:


 * -- the executable program itself, (v3.13 in PC-DOS 7)
 * -- pre-compiled profile for E's behavior
 * -- text file allowing modification of a few  defaults
 * -- text file used for E's F1 key help in Browse (read-only) mode

Since no tool was provided for building other profiles besides the supplied, PC-DOS users have limited access to the full exensibility offered by the version 3 of E (e3) available to IBM's own programmers. Still. it is a powerful implementation, with many features supporting the needs of general programmers.

For PC-DOS owners who have moved on to Microsoft operating systems such as Windows XP, E still runs fine in the "Command Prompt". Its main weakness in that environment is lack of support for long filenames, forcing DOS 8.3 filenames (eg, if editing file "ImReallyTooBig.text", users would have to use the backwards-compatible name "IMREAL~1.TEX"). When editing is complete, the long name is preserved, however.

EPM (OS/2)
EPM (E for the Presentation Manager, aka enhanced editor) shipped with OS/2 in addition to E (the System Editor) and tedit (the "tiny editor" available during OS/2 installation). While all are members of the E family, EPM is the most advanced. In addition to the features available in the PC-DOS version of E, EPM offers:


 * long filenames
 * selectable font (one font per document)
 * printing in WYSIWYG mode or draft mode
 * GUI design in accordance with Common User Access (CUA) principles
 * macro programming, both as keystroke recordings and using REXX language

Third parties offered free add-ons such as spell checking and syntax-directed editing of HTML files.

EPM for OS/2 Warp consists of 16 files:


 * -- the executable program itself (v5.5 in OS/2 3.0)

IBM later made available a tool to change existing profiles (*.EX) or build new ones. Netlabs eventually repackaged IBM's set of expansion files to be easier to install.