Today I finally released version 1.0 of my file picker. While I'm awaiting project hosting approval it can be fetched from http://github.com/alk/gpicker/tree/master.
This program lets you type part of filename (not necessarily prefix or substring) you want to pick. Unlike it's alternatives it's very fast and supports matching directory name. I also tried to make it smart. This means that it tries hard to place most likely candidates on top, so that you rarely have to select file, just press enter. Details can be seen in README.
It's not very useful as a standalone program, but is designed to be called from Emacs or any other editor/IDE. Emacs support is included. I bind it to Super-f (Super is a key with flag between Ctrl and Alt) and it takes me just few key presses and rarely more than a second to reach any file in project.
It's best to try it out to get its tremendous usefulness. But I'll try to illustrate it's power by few screenshots.
First screen demonstrates picker usage on linux kernel source. Nothing especially fancy here. Notice match highlighting and matching against directory name. And it's fast. On my machine startup takes much less then second. I think something around 0.2 seconds. It's noticeable, but still fast. Real-time filtration response is instantaneous (i.e. less than 0.1 seconds).
Usage on openjdk. Demonstrates usage on camel-cased names. Full openjdk sources are around 2 times larger then linux. It has 68k files. And on this size the filtration lag is noticeable. But it's still fast and usable. And you can always point gpicker to a particular subproject.