The high-performance DOS shell and erstwhile Windows competitor is now open source, with plans underway to create a modern SDK for Windows and Linux.

Video: Vintage computers from past 70 years battle in Grand Digital race Watch Now

GEOS is getting a fifth shot at life, as the 1990s DOS shell--despite the name, it is not an OS, in the strictest sense of the term--has been released as an open source project under the Apache 2.0 license by new owner blueway.Softworks. Old products seeing an open source revival is hardly new--Microsoft has done this with the first version of MS-DOS, the Windows 3.1 File Manager, and Calculator--though the path GEOS took to receive this new lease on life is more complex.

A brief trip down extended memory lane

For those who cut their teeth on computers like the Apple II and Commodore 64, GEOS brought a Mac-like GUI to comparatively lower-powered, 8-bit home computers. The team behind GEOS developed GeoWorks for PC in 1990. GeoWorks was also the basis of America Online for DOS. Substantial amounts of GeoWorks were written in fine-tuned x86 Assembly, making it decently more performant on Intel 386-based computers than Windows 3.0, which was released the same year. This high performance in constrained environments gave GeoWorks a protracted lifespan.

SEE: Virtualization policy (Tech Pro Research)

On PCs, GeoWorks had other incarnations, including "NewDeal Office" from 1996-2000, and Breadbox Ensemble from 2001-2009, both of which aimed at low-end computing and education markets. PEN/GEOS was a fork for Zoomer PDAs, such as the Tandy Z-PDA and Casio XL-7000, as well as the HP OmniGo, and the Brother Geobook, a netbook/word processor hybrid.

GeoWorks didn't quite achieve widespread success, despite the quality of the product. Brian Dougherty, the former CEO of GeoWorks, said "what killed us was that Microsoft realized what we had before the rest of the industry, they went to all of their OEMs and signed them to 2 year exclusive deals to put Windows on every machine," in a 2010 posting at The Economist, "Bundling with new hardware is the way you establish a new platform in the PC world and they simply froze us out of the market."

Additionally, a retrospective of GeoWorks lamented the lack of third-party developers, noting that "early on, you needed a Sun workstation to develop software for the platform, a deeply ironic requirement--essentially, you needed a $7,000 computer to develop software for low-end PCs."

Another shot at retrocomputing glory

Releasing PC/GEOS as open source came with significant hurdles, considering how often the platform changed hands. "After Frank S. Fischer, the former owner and long time GEOS enthusiast passed away, I worked with Breadbox's former CTO John Howard and Frank's wife, as the new owner, to acquire the rights to give PC/GEOS a future and a new home," Falk Rehwagen, former Breadbox employee and owner of new rights holder blueway.Softworks, told TechRepublic. "There always was the vision to make the technology available to the community to enable further developments, make it a living and developable system."

You can download PC/GEOS sources from GitHub, though the process of completely freeing it from its commercial past is still ongoing.

"Because Breadbox Ensemble uses licensed non-free parts, we decided to make it available for registered users only along the license agreement, to keep the system available to the world. At the same time we are separating the non-free parts and making PC/GEOS core available as open-source, forming #FreeGEOS," Rehwagen said. "Following our vision, together with making the source available, we are porting the tools to be usable together with the WATCOM open source compiler suite supporting 16 bit code generation. This enables us to make the PC/GEOS SDK available for Windows and Linux. This work is still ongoing, but progressing very well."

Rehwagen said he hopes to release a beta of GEOS 6, based on #FreeGEOS, in the next few months. Modernizing the platform is a priority: "We plan to move on with integrating available assets into #FreeGEOS as Double-Byte Character Set and Protected Mode support. Hopefully, we will be able to enable further developments to support state-of-the-art features and improvements of the system," he said, with hopes of developing a newly-active community of developers and users of GEOS.

Everything old is new again

For more on revivals of vintage computing technology, check out "Retro technology still makes sense for some IT projects," and "Using a Raspberry Pi Zero SCSI adapter to bring legacy and retro systems into the future" on TechRepublic, as well as "A professor found an Apple IIe in his dad's attic. And it worked" on ZDNet.

Open Source Weekly Newsletter You don't want to miss our tips, tutorials, and commentary on the Linux OS and open source applications. Delivered Tuesdays Sign up today

Also see