Not sure what development environment you are using. One thing that really seems to make a difference is raising the memory you allow your JVM to have during the build. For instance, in IntelliJ IDEA you can change the config file to greatly increase the RAM allowed the jvm, and also in Eclipse. Also, there's always the option of using an SSD instead of a standard hard drive which greatly increases the file I/O time (do they have SSD's for Macs?). The last thing would be to make sure you're running the most appropriate Ant target in build.xml. Although you have to be careful about it, sometimes you don't necessarily need a whole clean and build. On my Windows machine a whole clean and build might take 20 minutes but my distribution target only takes 5 minutes or so. That's on a 64-bit machine and giving the jvm I think 3GB. 2-3 hours sounds really slow, though. Labkey guys can probably give you some great advice on speeding that up.