I've long had this issue where opening large files, typically MySQL files as they get large quite quickly, but applications bundled with Windows, such as notepad and wordpad just don't cut it - I think because they read the entire file to memory before opening. Even Zend Studio is slow at opening it because it tries to add all of its fancy formatting to the MySQL document to prettify it.
Karl had the issue the other day where he wanted to open a large MySQL file, which was only around 11 megabytes, but although notepad opened it, it soon crashed when you scrolled down, and wordpad gave us a percent loaded but when it got to 100% it simply said something like "Formatting..." which we didn't wait around to see complete.
So I had myself a browse around the Internet to see what applicaions
were good at opening very large MySQL files. I came across
Scintilla's SCiTE which somebody had remarked on their observation that opening a ~100mb MySQL file in SCiTE took mere seconds. I didn't think that was at all possible, but I downloaded it anyway, and sure enough, SCiTE had loaded in the 11mb MySQL file, with colours as well, in a second at the very longest.
Very impressive stuff! And as I was so impressed, I decided to take a tour and found that it supports syntax highlighting in all the popular programming languages, as well as many I've never before heard of. It even has code collapsing as standard.