Earlier today, Epic Games CEO Tim Sweeney wrote an impassioned, thorough breakdown of Microsoft's Universal Windows Platform, accusing the company of monopolizing PC games development. He went as far to say the platform "can, should, must, and will die as a result of industry backlash."

　　Microsoft quickly responded, saying the Universal Windows Platform is a "fully open ecosystem, available to every developer, that can be supported by any store." Now, Xbox executive Phil Spencer has weighed in, too.

　　Across a series of tweets, Spencer said Windows has always been and will continue to be an "open ecosystem." He went on to say that more details on Microsoft's plans will be discussed at the company's Build conference later this month. Sweeney also chimed in, saying he's encouraged by Spencer's tweets and looks forward to what will be shared at Build.

　　Windows has always been an open ecosystem welcoming the contributions of hardware and software partners, and will always continue to be.

　　— Phil Spencer (@XboxP3) March 4, 2016

　　UWP is a fully open ecosystem, available to every developer, and can be supported by any store. Broad range of tools https://t.co/LqPcjRFzu9

　　— Phil Spencer (@XboxP3) March 4, 2016

　　We will discuss our next steps with the Universal Windows Platform at //build later this month.

　　— Phil Spencer (@XboxP3) March 4, 2016

　　@emiel1981 @TimSweeneyEpic is a friend and he pushes for what he believes. I agree UWP has to be open and that's what we are doing.

　　— Phil Spencer (@XboxP3) March 4, 2016

　　@cambaxter999 @Primey_ The feedback is great, even when it's negative, I read it and it impacts our plans. Thanks for being vocal.

　　— Phil Spencer (@XboxP3) March 4, 2016

　　And here is Sweeney's response to Spencer.

　　For lots more on this story, check out this in-depth SoundCloud interview Polygon conducted with Sweeney. In it, he talks about why he's so concerned with Microsoft's move, why he's speaking up now, and how things could be fixed in his estimation. He also reveals that he spoke with Xbox executives, including Phil Spencer, more than a year ago about his concerns.

　　"Being Epic, we want to fight for our rights, being independent software developers, to make PC software without Microsoft's permission," he said. "My tendency is to fight this really early on as they're starting to do it and not wait until they've gained so much momentum that we lose."