It's a day that some of Twitter's most high-profile developers have dreaded, though it's one they've long-known was coming: Twitter is finally shutting off some of the developer tools that popular apps like Tweetbot and Twitterific have heavily relied on.

With the change, many third-party Twitter apps will lose some functionality, like the ability to instantly refresh users' Twitter feeds and send push notifications. It won't make these apps unusable -- in some cases the apps' users may not even immediately notice the changes -- but it's a drastic enough change that developers have mounted a public campaign against the decision.

Now, Twitter is finally weighing in on the changes, after months of publicly declining to comment on the state of third-party Twitter clients. The verdict, unsurprisingly, is complicated.

The company is adamant that its goal isn't to single out these developers. The company is retiring these APIs out of necessity, it says, as it's no longer feasible to support them."We are sunsetting very old, legacy software that we don't have an ability to keep supporting for practical reasons," says Ian Caims, group product manager at Twitter.

At the same time, though, the company has also made a conscious decision notto create new APIs with the same functionality. Here's how Twitter's senior director of product management Rob Johnson explained the move in an email to Twitter staff:

"It is now time to make the hard decision to end support for these legacy APIs — acknowledging that some aspects of these apps would be degraded as a result. Today, we are facing technical and business constraints we can’t ignore. The User Streams and Site Streams APIs that serve core functions of many of these clients have been in a 'beta' state for more than 9 years, and are built on a technology stack we no longer support. We’re not changing our rules, or setting out to 'kill' 3rd party clients; but we are killing, out of operational necessity, some of the legacy APIs that power some features of those clients. And it has not been a realistic option for us today to invest in building a totally new service to replace these APIs, which are used by less than 1% of Twitter developers."

Talk to some of these developers, though, and what they are more worried about isn't the loss of the APIs, but what the change represents. To them, it's the latest sign that Twitter is ready to take a more active role in discouraging people from using alternative Twitter apps in the first place.

"The issue with these changes is that they mark a shift in Twitter's mindset around third party apps as well as being the first actionable item to attempt to undermine their market-share," says Luke Klinker, the developer of Talon.

Meanwhile, Twitter says its goal is to point its users to the "best Twitter experience," noting that more recent additions, like Periscope and Moments, aren't supported in third-party apps.

"We feel the best Twitter experience we can provide today is through our owned and operated Twitter for iOS and Android apps, as well as desktop and mobile twitter.com," Johnson wrote in a blog post.

This kind of back an forth isn't new. Twitter has a long, and sometimes messy relationship, with third-party clients. In the early days of the service, the only options for Twitter iPhone apps were from third-parties, which helped make them -- and Twitter -- popular. It's why Twitter acquired Tweetie, which would become the first official Twitter app, in 2010. Some of these apps are also credited with creating what are now iconic features of Twitter like the mute button. Even the word "tweet" was coined by Twitterific before Twitter adopted the term.

But as Twitter matured, and had its own apps, the company changed its stance. In 2011, the company told developers not to build Twitter clients, and in 2012 it imposed API limitations meant to discourage them more actively (sound familiar?).

Now, the vast majority of Twitter users access it through the company's own apps and website. But third-party apps remain popular with many power users.

"One thing third-party apps have going for them, and will continue to have going for them, is all the things that Twitter doesn't do and does badly," says Ged Maheux, cofounder of Iconfactory, which makes Twitterific. "Not presenting your tweets in chronological order; there's no promoted tweets, there's no other people's likes in the timelines. All this other stuff that's Twitter added don't clutter your timeline on third-party apps."

There's also the fact that Twitter doesn't currently have a great experience for Mac. Twitter's official Mac app is dead, and TweetDeck's Mac app hasn't been updated since 2015. (Twitter senior product manager Patrick Traughber says the company is "continuing to invest in TweetDeck, along with the core Twitter apps.)

But despite the messiness with third-party clients, Twitter says it's still committed to the open platform -- and the developers -- it first embraced years ago.

"We're very committed to investing in our developer ecosystem and our developer APIs that help them build new and interesting things," says Caims. "This is by no mean a signal that we're not investing in developers."