... in the "Files" section. When using the manual download from there, you also need to include the following jar files in your project:
juel-api-2.2.7.jar, juel-impl-2.2.7.jar, commons-beanutils-core-1.8.3.jar and commons-logging-1.1.1.jar
API: http://colllib.sourceforge.net/apidoc/
NEW: colllib switches to Java 8 starting with colllib 2.0. If you depend on an older VM-version, please stick to colllib-1.6.