memo.xight.org

- Google Code Search
http://www.google.com/codesearch

- Koders - Source Code Search Engine
http://www.koders.com/

- codefetch
http://www.codefetch.com/

- Krugle - Code Search for Developers
http://www.krugle.com/

- byteMyCode
http://www.bytemycode.com/

- Codase - Source Code Search Engine
http://www.codase.com/

- Java Examples - JExamples.com
http://www.jexamples.com/

- DocJar: Search Open Source Java API
http://www.docjar.com/

- Prospector Demo
http://snobol.cs.berkeley.edu/prospector/

- KickJava.com: Java API By Example, From Geeks To Geeks.
http://kickjava.com/

- Jarhoo
http://www.jarhoo.com/content.jsp

- All The Code - Source Code Search Engine
http://www.allthecode.com/

- Code Search - O'Reilly Labs
http://labs.oreilly.com/code/

- Reference
@IT - 見つけて得するソースコード専用の検索エンジン
http://www.atmarkit.co.jp/fjava/column/andoh/andoh33.html