What ist with vim and Emacs? Did you try them? I loaded files bigger than 1 GB with them - but this was on Windows.

When do you need to actually open and edit a 500 mb ascii file instead of just processing it with one of the many Unix command line tools that can handle a 500 mb file just fine? (I realize it hypothetically does happen, the question refers to frequency.)

XYZ files from Multibeam surveys. Windows user. Sometimes I need to look at the contents of the file - EG: remove x number of "headers" from the ASCII file.

when you are on windows?

There are alternatives to UNIX command line tools available on Windows (such as Powershell, for example), as well as ports of them (Cygwin etc). An editor as a replacement for those isn't really the best way to go.

I just tried a 1.1 gig file with MacVim and didn't have any issues.

I suspect that BBEdit (http://barebones.com/products/bbedit/) wouldn't have a problem with a 500mb file.

BBEdit beach balled for about 30 minutes on my 7 million line, 500 meg test file, before I gave up and killed it.

I think everyone is talking in Mac context here. It's more laggy than Textmate when I open a 500-line-file. Unfortunately I don't have 500MB ASCII file to test.

Textmate freezes when I try to open any big file, like 50MB. Sucks. Otherwise great.

Grab the free version of Visual Studio (Express).

look up "thegun" editor (windows)