With this plugin, your vim comes to automatically opens popup menu for completions when you enter characters or move the cursor in Insert mode. It won't prevent you continuing entering characters.
First install dependency L9
Then put all files into your runtime directory. If you have the zip file, extract it to your runtime directory.
You should place the files as follows:
<your runtime directory>/plugin/acp.vim <your runtime directory>/doc/acp.txt ...
If you disgust to jumble up this plugin and other plugins in your runtime directory, put the files into new directory and just add the directory path to 'runtimepath'. It's easy to uninstall the plugin.
And then update your help tags files to enable fuzzyfinder help. See :h add-local-help for details.
Copyright (c) 2007-2009 Takeshi NISHIDA