Valve has invited members of the public to become part of tests for its forthcoming video games hardware.
The firm said it would send out 300 prototype Steam Machines, which are designed for use in the living room.
The company added that other manufacturers would begin selling devices running its games-focused operating system SteamOS next year.
The move was described as "audacious" by one analyst, but another had doubts about who would buy the devices.
Console makers - including Sony, Nintendo and Microsoft - typically do not let the public take hold of their hardware until it is ready for release.
Valve currently offers its Steam platform as software running on others' systems - Microsoft's Windows, Apple's Mac OS, Sony's PlayStation 3 and various Linux-based software. It acts as a marketplace and a way for gamers to play against each other and share titles.
Valve uses Steam to promote its own games - including Half Life, Portal, and Dota 2 - as well as those written by third-party developers, from whom it takes a cut of the sales.
It does not release sales statistics - but estimates from consultancy IHS Screen Digest suggest Steam is responsible for 75% of PC game sales, bringing in about $1bn (£620m) in 2012.
There are close to 3,000 games on the service.
Valve said that members of the public picked would receive a "high-performance prototype" designed for users who wanted "the most control possible" over their hardware.
"The input from testers should come in many forms: bug reports, forum posts, concept art, 3D prints, haikus, and also very publicly stated opinions," it said.
It acknowledged that the majority of games in its library would not run natively on its equipment during the beta trial, but added that "the rest will work seamlessly via in-home streaming", indicating that they can be used if run on another PC.
The firm said a "small number" of applicants would be chosen according to their past contributions to its community, but the majority would be picked at random.
It added that those taking part would receive the boxes this year and could make changes to the hardware and software, including the installation of another operating system.
The news comes two days after the company unveiled details of SteamOS. A third announcement is scheduled for Friday.
"It's an audacious idea to release a Linux-based system this late in the game," said Lewis Ward, a video games analyst at market research firm IDC.
"They're going to listen very closely to their customers to see what works and doesn't work and they will crunch a lot of numbers - what we call big data.
"People may find the experience much worse than existing consoles - and it's natural to compare things - but I assume that Valve has done its homework in advance and is not going to put this out there into their hands until it feels that it's solid."
However, another industry watcher said he was surprised more information had not been provided, adding that Valve still had to prove why consumers needed another box to connect to their TV.
"I don't know who they are trying to sell the Steam Box to," said Rob Crossley, associate editor of Computer And Video Games news site.
"If they are trying to sell it to the PC audience you're saying to someone who has already purchased a £1,000 machine that they should buy another £500 machine on top to play the same games in a different room.
"That is strange proposition and I struggle to think that will be successful."
Valve has indicated, however, that a forthcoming announcement about a controller might help woo the public.
"We have some more to say very soon on the topic of input," it said on its site.
The company's founder, Gabe Newell, told the BBC in March that it was working on a way to use sensors to measure a gamer's body states.
"If you think of a game like Left For Dead - which was trying to put you into a sort of horror movie - if you don't change the experience of what the player is actually feeling then it stops being a horror game," he explained.
"So, you need to actually be able to directly measure how aroused the player is - what their heart rate is, things like that - in order to offer them a new experience each time they play."
Mr Crossley said that this could be a winning idea.
"Valve two years ago hired a behavioural psychologist to read different things that happen to the player as they play video games," he said.
"The intriguing thing is that if a game can know how you are feeling then all of a sudden some incredible things can happen. When you are calm it can spook you, when you are stressed and fatigued it can reduce the challenge.
"This is in some ways a utopian vision for the future of video games."