From the post:
In 2004 Mongoose Publishing released the d20--?based Conan: The Roleplaying game Over the next six years followed it with a second edition and a variety of source materials. adventures, and other guides for roleplaying in the Hyborian Age of Conan, as created by Robert E. Howard.
In 2016, Modiphius Entertainment launches Robert E. Howard’s Conan Adventures in an Age Undreamed Of, using the 2d20 system. With the transition of the Conan license came access to the prior materials published by Mongoose. These are now being made available to Kickstarter patrons, so that players can use this material as they create new adventures in the Hyborian Age.
Two members of Modiphius’ all--?star writing team — Vincent Darlage and Ian Sturrock — were foremost among the authors of the earlier d20 game, beginning with Ian’s work on the core rulebook and earliest sourcebooks, to Vincent’s prodigious efforts at expanding the coverage of the Hyborian Age.
For this reason Modiphius has asked each of them to contribute to the new game line, additionally putting Vincent to the epic (D5) task of creating this conversion guide, with Ian reviewing it for fidelity to the rules he created in 2004.