Brett Terpstra has written a bundle for the cutting-edge text editor TextMate which enables the creation, editing and deleting of Backpack items within the editor.

TextMate won the Apple Design Award for Best Developer Tool at WWDC this year. It shares some interesting design features with Mail.

Like Mail, it is built on a “lean but extendible” philosophy. An array of bundles allow users to extend the app in ways that suit them, rather than loading it up by default with the bloat of every possible feature. For example, this blog is written with TextMate’s blogging bundle , crucial to me, but not important to every TextMate user.

Unlike Mail, TextMate developer Allan Ogaard encourages bundle developers by opening up the guts of the editor so that third-party developers can easily create new bundles. With Mail’s undocumented API, third-party Mail.app bundle developers can only beat their heads against their monitors until the code works. (Although some helpful notes on Mail’s plugin API exist.)

Brett’s Backpack plugin allows access to pages, reminders and lists. (The updated version released yesterday adds list support.)

All the commands are linked to the ⌃⌘R keyboard shortcut.

This pops up a list of all the options, which can be selected by pressing the required number or with the up and down arrows.

New items are created through a pop-up window:

Editing is done via a list of all the available items on your Backpack pages. Again, items can be quickly selected by number.

Of course, there are other ways to integrate Backpack into your workflow: a Dashboard widget (pictured), a Firefox extension , the stand-alone Packrat app, a plugin for Quicksilver and more.

If you spend a lot of time in TextMate, this bundle is a nifty way to get stuff into Backpack quickly and to edit existing items without switching around.

In other TextMate news, the app has been ported (sort of) to Windows.