At Microsoft's Professional Developer Conference, Seesmic's founder and CEO Loic Le Meur just announced that the company will release a native Windows version of its popular Twitter client later today. Seesmic developed this client on top of .NET. As Le Meur told us yesterday, the new client will be faster and use significantly less memory than the current AIR client. In addition, Seesmic will now also feature a Firefox-like plugin infrastructure that will allow developers to extend the application through a new, built-in API.

As usual, Seesmic will first make this new Seesmic for Windows client available to members of its Team Seesmic beta test community. Signing up for Team Seesmic is easy and you will immediately get access to all of Seesmic's public beta products.

Le Meur told us that a native Windows client was something that Seesmic's users had been requesting for quite a while. The Seesmic team worked on this new client for the last few months, though the company managed to keep this development under wraps and today's release comes as a surprise. While there are quite a few good native Twitter clients for OSX, the most popular Twitter clients on Windows are currently AIR apps.

Features

Being a native client, Seesmic can now also make use of some of Windows' built-in features like a system-wide spellchecker or Windows 7's location services. While Twitter hasn't launched it's location API yet, Seesmic will now be able to tab into this data quickly.

The new client will also allow users to drag and drop their friends' avatars into user lists.

Just like the current beta version of its AIR app, Seesmic for Windows will support Twitter's userlists and while the look and feel is similar to the AIR app, the Windows client also features vertical tabs in the sidebar that allow users to quickly switch between different views (all, accounts, userlists and searches).

Plugins for Seesmic

For developers, of course, the new plugin infrastructure also means that they can now offer their services directly in a Twitter client. The current version already showcases plugins from TweetMeme and MrTweet. According to Le Meur, this will also allow other Twitter-like services to build their own plugins and build their own columns in Seesmic without having to establish a formal relationship with the company. In a few weeks, Seesmic will launch a plugin gallery to showcase these extensions.

What About the AIR App?

Seesmic will continue to develop its Adobe AIR client for the time being, though chances are that the company is also looking at developing a native Mac client.