Apache Lucene has indexers for many languages, including English and Arabic. It's a building block, though, so you'd have to build your search application around it. Or check out the Apache Solr project, which uses Lucene underneath.
If you're serious about Lucene at ll, then you need to read the "Lucene in Action" book; it's too powerful a library to pick up just from snippets of code found around the web, IMO.
Ping & DNS - updated with new look and Ping home screen widget