LT Toolkit from the now-defunct drcauto was an add-on for AutoCAD LT that provided LISP and other capabilities that Autodesk disabled. Autodesk hated this, of course, but the late Gary D’Arcy made sure everything was done legally so it couldn’t be stopped even by Autodesk’s hyperactive legal team.
If you are a user of LT Toolkit and you want to keep using the software now the company has closed down, you may find this information from Evan Yares useful:
I’ve gotten in contact with Leonard Liang, the former key developer at DRCauto. He’s asked me to send any Toolkit Max users to him, and he will help them. His website is www.cadsta.com. His email, at that domain, is “leonardl”.
Source: a comment in this this WorldCAD Access post. If you don’t read comments, you may well have missed this, so I thought it was worth repeating.
Edit: events have overtaken this news since it was written. Please see here and here.
Unfortunately, Leonard Liang a former employee of the DRCAuto company does not have legal rights to the software or any other part of the company including its database of users, source code or software authorisation process.
CAD International have purchased the IP of the former company and are the only legal avenue though which users can obtain re-authorisation codes or software developed by DRCAuto.
We would recommend appropriate caution should be exercised by parties promoting or dealing with alternative avenues of supply
drcauto software does not work on Windows 7, or the 64bit version of AutoCAD. The CADSTA software does! CADSTA does not supply drcauto products. Rather, they offer an alternative product, written from the ground up.