<p>I'd like to know what are the most useful JQuery plugins. I'm particularly interested in  those which are likely to be useful in general UI development, such as <a href="http://tablesorter.com" rel="noreferrer">Tablesorter</a>, rather than those which serve uncommon needs.</p>

<p>If you could provide a very brief description of the plugin's purpose, that would be really helpful.</p>

<p>Thanks,
Don</p>

I'll list one I'm working on...
My jLINQ plugin
is a jQuery version of .NET LINQ. It's made for working with in-memory collections (not talking directly to the server) and let's you use syntax similar to the following.
```
```
var results = $.from(data)
    .ignoreCase()
    .startsWith("firstName","m")
    .or("n")
    .isNot("administrator")
    .orderBy("lastName")
    .select();
```
```
It supports a bunch of other commands that you find in LINQ for ordering and grouping along with most of the selection commands like contains, between, greaterThan, etc...
Here is a demo
-
It's stable, but still in progress
Maybe not must have, but might be useful as it progresses...