“3D Browser 5.51 is a major release and offers you more than 40 new features or improvements in comparison to 3D Browser 5.1. You can find an extended list of improvements at What's new about 3D Browser 5.51.”

(continued...)

Also :
“New: Polygon Cruncher for 3D Browser 5.51

Polygon Cruncher is now directly accessible through 3D Browser.
Polygon Cruncher optimizes a 3D scene, keeping all its details. Just opens a scene with 3D Browser and optimize it using Polygon Cruncher. Save results using one of the available 3D exported format (3DS, Lightwave, DXF, Cinema4D...).”

... and ...
“Special offering: save 25% on 3D Browser now!

Register now and save 25% on 3D Browser 5.51 price (29 $US instead of 39$).
If Polygon Cruncher interests you, you can also save 20% buying 3D Browser and Polygon Cruncher at the same time.”