LPEX (text editor)
| Company type | Software |
|---|---|
| Industry | Text editing software |
| Founded | 1985 |
| Founder | Mike Cowlishaw |
| Products | Text editor with live parsing and syntax highlighting |
LEXX is a text editor recognized as one of the earliest to implement live parsing alongside colour syntax highlighting for both marked-up documents and programming code. Created in 1985 by IBM's Mike Cowlishaw, it was originally designed to assist lexicographers working on the 'New Oxford English Dictionary' (NOED; the second edition of the Oxford English Dictionary) under Oxford University Press. The application has historically operated—and continued to do so as of 2018—on mainframe systems running VM/CMS. Its development drew upon Cowlishaw's previous editors, such as STET, and took advantage of advanced colour terminal hardware like the IBM 3279. LEXX supports programmability through dynamically loaded compiled commands, frequently written in PL/I, and interpreted commands, typically authored in REXX, which is indicated by the 'XX' suffix in its name.
The editor uses parsers that are loaded dynamically to categorize tokens, assigning different fonts and colours accordingly. It also provides features such as indentation to visually represent file structure and allows users to format text by concealing certain token classes, for example, tags.
LPEX ('Live Parsing Editor') represents a modern reimplementation of LEXX, originally created for the OS/2 and AIX platforms. It has since been extended to function on Windows, Linux, and within the Java JVM environment.