TinyEdit is tiny, and tautological statements are tautological statements. Weighing in at just under 600K, it's a perfect fit for a flash drive or a cheap netbook. Combined with its syntax-highlighting features and tabbed interface, it's the perfect text editing program to go on any sysadmin's digital, or actual, Swiss army knife.
Its built-in syntax highlighting supports an impressive array of languages and markups, focusing strongly on those used for scripting, batch programming and web development, including PHP, SQL, AWK and CSS, among many others. However, this list is immutable, the user can't add a language or change the highlighting used, nor can a user tell TinyEdit which files on his system should use which highlighter.
If you use a non-standard extension for a given file type (for example, using .txt for HTML files as a means of avoiding some types of autorun exploits), there's no way to get TinyEdit to process it as if it were HTML. The exact file extensions it associates with file types are not explicitly listed, but testing on a variety of files shows it follows most expected conventions. You should rarely be surprised by what it does.
TinyEdit manages its small size by keeping its feature list small. To paraphrase Henry Ford, you can view your text in any font you like, as long as the font you like is 12 point Courier. TinyEdit provides basic load/save functionality, search and replace, unlimited undo and redo, word wrap and not much else besides the ability to have multiple files open concurrently in a tabbed interface.
It's absolutely not going to replace your favorite IDE (such as Eclipse) or full-featured programmer's editor (such as UltraEdit), but it's not trying to. It's trying to give you a better tool for quick-and-dirty text editing with limited system resources than Notepad does, and at that, it succeeds.
As such, I recommend TinyEdit for anyone who even occasionally needs precisely this: a small, syntax-aware text editor that fits in a single .exe and just runs from wherever it's located. It's freeware, so it is even easier on your financial resources than it is on your system resources.