Is there a download link to previous versions of Unity 3d? Especially 2.5?
Here is the download link to 2.5 pc:
http://download.unity3d.com/download_unity/UnitySetup-2.5.1.exe
and here is the link to 2.6 pc:
http://download.unity3d.com/download_unity/UnitySetup-2.6.0.exe
PC Editor: 3.0 | 3.1 | 3.2 | 3.3 | 3.4 | 3.4.2 | 3.5.6
Mac Editor: 3.0 | 3.1 | 3.2 | 3.3 | 3.4 | 3.4.2 | 3.5.6
iPhone: 1.7.0
PC/Mac installers, release notes and built in shaders are found at this web page dating back to Unity 3.0. It does not list 2.x content.