id Software currently has a number of job vacancies open at its Dallas offices where the studio is hoping to hire new staff members to work on the development of a "long-running iconic action FPS".
The open positions can currently be found listed on Zenimax's website. As well as stating that the developer is hiring staff to work on an already existing IP, a number of vacancy posts on the site may also provide further clues as to what that might be.
Listed under the job description for Skybox Artist, the studio says that it is looking for someone to join its existing team to provide "AAA-quality sci-fi and fantasy environmental vistas and skyboxes". While id has by no means confirmed what franchise new staff will be working on, its reference to a "sci-fi and fantasy" aesthetic could suggest that the studio is looking to begin development on a new Doom entry. Alternatively, the gothic industrial look of Quake could also be considered within the realms of sci-fi and fantasy.
Doom Eternal, id Software's last entry into the Doom series, was released last year and faired well among critics and fans alike. Feel free to check out our review of the game, which we awarded it a 9/10. While the strong critical reception could be enough to speculate that the studio may be returning to the series again for a sixth Doom, there are also a number of factors that could get Quake fans excited too.
The release of a remastered version of Quake earlier this year following its announcement at QuakeCon may suggest that the studio has been testing the waters before looking to re-enter the franchise further in the future.
Jared Moore is a freelance writer for IGN. You can follow him on Twitter.