Proof Pad
Try the new online version of Proof Pad!

Proof Pad

A modern development environment for ACL2 with all the trimmings.

Download for Windows (64-bit) Download for OS X
Download for Windows (32-bit) Download for Linux
Other platforms

The Proof Pad icon is based on an image by Deutsche Fotothek. Used under the Creative Commons Attribution-ShareAlike 3.0 Germany license.