There's support for viewing 3D images in many different ways: side-by-side, colour and gray anaglyphs, interlaced, above/ below and more. A convenient "flashing" option quickly switches back and forth between the two images, allowing you to get a feel for the 3D effect even if you don't have a viewer.
The real power here comes from StereoPhoto Maker's ability to create and adjust 3D images, though. At its simplest, you might open a 3D picture and use the cursor keys to re-align images, one pixel at a time. But if you're working on a larger scale, the author claims StereoPhoto Maker 4.52 can "automatically batch-align hundreds of images and mount them to the 'window'".
In StereoPhoto Maker, you also get the option to create simple web pages which, in theory at least, allow you to share your favourite 3D pictures with others. We say "in theory" as it didn't work well for us, but if you have more luck then this could be very useful.
Download: StereoPhoto Maker 4.52