I cannot really remember when I first starting using the image viewer XnView on all of my Windows systems as one of the programs to browse images on it, but it certainly must have been a decade ago or even longer than that.
XnView 2.0 has been released a couple of days ago and I have not really seen any review or announcement on other technology blogs. The good news for existing users is that the program has not been changed visually in this new version. No fancy user interface changes that get in your way which many existing users will certainly appreciate.
XnView 2.0 is available in different versions. You can download a minimal, standard or extended version from the developer website which are all free and available as portable versions or setup files. The versions differ in regards to the plugins and addons that they ship with. The minimal version ships without any, while both the standard and extended version ship with additional plugins and extras.
You can also download additional plugins and add-ons separately from the same download page. These optional modules may add support for additional image formats, like WebP, Paint.net, WMP, DjVu or JPEG2000, and additional functionality to the program. Interesting add-ons include options to integrate the excellent image optimizer Riot in to XnView, add support to send images by ftp or to the image hosting site ImageShack, or the option to view contents of archive formats without unpacking them.
XnView 2.0 ships with a new Metro toolbar style that you can - but do not have to - activate in the program's settings. Apart from that you will find mostly fixes to various program modules and features in this new release. There is not really a lot that you can improve in regards to the picture viewer anyway so that should not come as a surprise.
The new version of the application can be downloaded from the official website. If you are interested in all of the changes check out the what's new text file that the program ships with.