My company makes a software package called Oratorio that’s designed for presenting lyrics in a church service. Because we’ve been getting (and paying attention to) lots of really good feedback from its users, we’ve been able to make it progressively better and more feature-complete.
One of the sticking points for some people has been that the program bogs down a bit in some cases. I’ve been devoting a fair bit of thought to how to speed it up, and had a couple epiphanies that have helped significantly. I put the last of those changes into place this morning, and have been delighted and suprised with the performance increase I’ve seen, especially under Mac OS X. (Mac OS X has beautiful font smoothing that makes type looks great, but takes about 5x as long as any other OS to draw a piece of text. Oratorio used to do a lot of text drawing, but now does much less behind the scenes, which results in a very pronounced speed increase.)