DevBridge Ajax Autocomplete is a good alternative to jQuery UI's autocomplete. It's built with focus on performance - results for every query are cached and pulled from local cache for the same repeating query. It's smart enough to stops sending requests to the server for other queries with the same root.
- Search local or ajax data
- Format result
- Using localCache to reduce query requests
- onSelect, onSearchStart, onSearchComplete events for search result manipulation
- Currently supported browsers: IE 7+, FF 2+, Safari 3+, Opera 9+
- and many more options.