After the publication of T-EPT, Guardians of Order ceased to publish. They had contracted Ian Sturrock to produce a d20 version of Tekumel and he had a manuscript, but no publisher when GoO dissolved.

I talked to Professor Barker a number of times on this and he agreed that I should try to revive the manuscript. Getting the rights from Ian, I have begun a set of creative playtests to reflect the world of Tekumel. After these are more complete, a manuscript will be submitted to Professor Barker for approval.

The website for this test is billhartley.com. You can sign up there to see how the playtest proceeds, make comments, etc. Should you want to be a playtester, email me (admin on the site) and I'll send you a non disclosure document, which once signed and submitted to me will get you a copy of the manuscript to play with. This is designed mainly to protect the rights of all concerned, including the creators of T-EPT.

-Bill Hartley

Bill has taken down the website he mentions above, but he is still working on the d20 project. More info in this other thread:
viewtopic.php?t=324

I've added the manuscript to the tekumel project. We'll work in with the good folks there [including Prof Barker] to complete and set things up.
Meanwhile, I know you people have access to the temporary d20 rules as well as the all important spells by Chris so hang in there!
Bill Hartley

Tlakotani description will be put in the rules on publication..
Don't expect more than the Gij and sons type of stuff... maybe some undying wizard drop ins, you know... business as usual

The above states something about adding d20 to the Tekumel Project. That is incorrect; it has been submitted to the Tekumel Foundation for editing and further action.

-Bill Hartley