具有类似于shell命令行完成的TAB完成/自动填充的Ajax自动完成（或自动提示）？

I'm implementing a AJAX autocomplete/autosuggest feature, and not only do I want to do the usual show suggestions that are similar to what the user typed, but I'd like to let the user do partial completions to save typing. I'm implementing a AJAX autocomplete/autosugges