Twitter APIs for Java

I've been messing with Twitter APIs in Java lately. I've come across three open source projects so far, which oddly enough are not listed anywhere all in one place, so here's the list:

• java-twitter (http://code.google.com/p/java-twitter/) License: Apache 2.0
  
• JTwitter (http://www.winterwell.com/software/jtwitter.php) License: LGPL
  
• Twitter4J (http://yusuke.homeip.net/twitter4j/en/index.html) License: "BSD-style"
  

These are listed in the order I came across them.

I've used java-twitter to build a couple small things. The project is active and being updated regularly, and the code seems to work. It uses a lot of dependent libraries, one of which you need to build yourself (Google Prototype Buffers). The API has been recently updated to use a builder-style model which is a little complicated but still not hard to understand.

Haven't tried the other two yet. At first glance, JTwitter is the simplest; Twitter4J seems to have the most obvious usage model and clear Javadocs; it wants to be donation-ware.