Scripting Toolkit
In the feed I use to track new AppExchange applications that get published, I saw an interesting one today from Salesforce Labs called the Scripting Toolkit.
It only installs 1 web tab and the tab points to http://www.interclasse.com/toolkit/ and sends parameters such as your Org ID, Session ID and User ID over to the page. After downloading it, I was a little suspect of the URL, so I went directly to http://www.interclasse.com/toolkit/ and was able to get what I needed.
Basically, the scripting toolkit is a “JavaScript Ajax wrapper around the API”. It only runs on Windows. It is very much like the AJAX toolkit except it also allows you to host your own JS files and run them via a command line rather than using a browser. In other words, you could use it to schedule things or just run JS files (AJAX Toolkit) from your desktop. There are a number of good examples in the documentation. It’s yet another useful way to use the API.
I would assume accessing it via the web tab in the AppExchange package is fine, but you can also get what you need directly from http://www.interclasse.com/toolkit/.