LaunchBar is an OS X text based launcher like QuickSilver and Butler. In fact, I think it’s the first one on OS X (and maybe on any platform?), version 1 was a NEXTSTEP and OPENSTEP application (you can get that version for free, BTW). You should absolutely use one of those three applications anyway.
Even if it is not free and lack a plugin API, I still prefer it over QuickSilver. It’s faster and gives better results IMO. Most of the features added via plugins in QS can be added to LaunchBar with scripts.
You can find search templates, scripts, etc. on the forum.