Downloading Rhino RDK 5.1.2011.407 from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this software available. You can execute Rhino RDK on Windows XP/7/8 64-bit.
The following versions: 5.1, 4.1 and 4.0 are the most frequently downloaded ones by the program users. The program is included in Photo & Graphics Tools. The actual developer of the free software is Robert McNeel & Associates.
The Rhino RDK installer is commonly called RhinoStart.exe, Rhino.exe, Rhino3.exe or Rhino4.exe etc. According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software.
From the developer:
The Rhino RDK is a collection of tools that extend the Rhino application platform with visualization specific capabilities.
Features:
-Extensible Material, Environment and Texture editor.
-Frame buffer implementation with post and channel handling.
-Pre-process custom mesh provision interface for 3rd party developers.
-Built in procedural textures, including wood, marble, granite, noise generators, perturbers and so on.
You may want to check out more software, such as SimLab 3D PDF From Rhino, X-55 Rhino or WinAgents Rhino Terminal, which might be similar to Rhino RDK.