Consider this the end of an era. After 15 years of working together, first at PayPal and then at YouTube and most recently at incubator Avos Systems, YouTube co-founders Chad Hurley and Steve Chen are headed in different directions.

Avos is pivoting, in a sense, and transforming from an incubator into a single company working on a single product: MixBit, a mobile video platform. MixBit has been Hurley’s baby from the beginning, so he will be taking the helm there. Meanwhile, Steve Chen will move over to Google Ventures (where our own Leena Rao is headed to be a partner) as an entrepreneur in residence.

Chen and Hurley founded Avos Systems in 2011 to give both the freedom to pursue multiple projects. The incubator ran similarly to an Expa or betaworks in that the projects were chosen by Hurley and Chen, and stayed within a relatively closed environment. Avos was also unique in that it used a ready-made base of APIs and code snippets to help entrepreneurs get off the ground faster.

“We were working on nine products at one time, which sounds astronomical, but it wasn’t based on the way Avos was structured,” said Chen. “I’d say about 40 percent of all websites and iOS apps are built on the same shared technology, built and rebuilt and rebuilt again. With Avos all the servers and authentication and security were all written and handled, so it was much easier to test out new ideas.”

But of all the ideas, MixBit was the one that got the attention.

Hurley had dreamed for years of building out video on mobile the same way he did with YouTube, and so MixBit was born. Being the founders of YouTube, Hurley and Chen knew they couldn’t get MixBit out the door for testing without making an announcement. So when the app launched into a beta testing period in October, the team made an announcement to get people on the platform and get feedback.

Then they went silent.

“To us, that was really just a period in which we could watch how people use the service and see what they want,” said Hurley. “Plus, it gave us time to get everything settled with the transition from Avos to MixBit.”

But what is MixBit?

MixBit is an app that lets users record clips and then create videos collaboratively. You can choose clips based on location or friendships, or just choose from the whole bunch of them. The service is interesting, and definitely a signal toward where we’re going with mobile video, but it may be before it’s time.

As for Avos many of the projects also circled around video consumption, creation and collaboration, so pivoting from Avos into MixBit kept most of the team together. There are still offices in New Zealand and San Mateo, comprising between 20 and 25 employees, who will now all be working on MixBit.

The team prepped for the transition by selling off Delicious and ensuring that any other engineers or developers at Avos were ready to do something more independent. Turns out that only a few developers in the Beijing operation will be doing their own thing, with the rest of the remaining Avos team joining MixBit.

I asked the two entrepreneurs how they feel about working separately after spending so much of their professional careers side by side.

“We’ll be fine,” said Hurley, laughing.

“We won’t be fine,” Chen said with a smile. “Actually, it was a very personal and difficult decision to make, but with the decision to turn Avos into MixBit it became pretty clear. MixBit was Chad’s idea before we started Avos and even at YouTube, and if I feel driven to work on other projects, then I’m just getting in the way of MixBit and the team.”

That said, the duo seems excited about the new opportunities ahead. “I can always stop by Steve’s and steal some food every once in a while,” Hurley said.

Chen wouldn’t go into much detail about what he plans on building at Google Ventures, but he did explain that part of the draw of GV was being around the younger, fresher minds in tech. “Chad and I have always been on the inside of one company, so the opportunity to start from higher up across multiple industries and talk to the people at the forefront of the future… that’s something that is exciting and alluring to me.”

Though he wouldn’t speak up about what he specifically wants to build, he did hint that it will probably be related to media.

“There’s only so much that I know about, and some of those things are media and the way we distribute media,” said Chen. “But it’s a very different time from when we started YouTube, before the iPhone and the cloud were so in play.”