Microsoft Build 2025: news and announcements from the developer conference

Microsoft is working on a new “Cross Device Resume” feature for Windows 11 that works similarly to Apple’s Handoff feature in macOS. The feature was spotted in a Microsoft Build 2025 session, before Windows Central noticed Microsoft editing out the demo that showed a mobile Spotify session resuming on a PC.

“When you open the app on your mobile device or tablet, Windows can show a subtle badge right on your app’s taskbar icon,” explains Aakash Varshney, a senior product manager for cross devices and experiences at Microsoft, in a “Create Seamless Cross-Device Experiences with Windows for your app” Build session for developers. “It’s a visual nudge that when clicked launches your app directly into the task, delivering a smooth intuitive handoff from PC to phone.”

Microsoft’s head of security for AI, Neta Haiby, accidentally revealed confidential messages about Walmart’s use of Microsoft’s AI tools during a Build talk that was disrupted by protesters.

The Build livestream was muted and the camera pointed down, but the session resumed moments later after the protesters were escorted out. In the aftermath, Haiby then accidentally switched to Microsoft Teams while sharing her screen, revealing confidential internal messages about Walmart’s upcoming use of Microsoft’s Entra and AI gateway services.

Microsoft’s Build developer conference has been interrupted by a protester for the second day in a row. Microsoft’s head of CoreAI, Jay Parikh, was on stage discussing the company’s Azure AI Foundry efforts when a Palestinian tech worker interrupted his keynote to protest against Microsoft’s contracts with the Israeli government.

“Jay! My people are suffering!” said the unnamed tech worker. “Cut ties! No Azure for apartheid! Free, free Palestine!”

Microsoft is starting to integrate AI shortcuts, or what it calls AI actions, into the File Explorer in Windows 11. These shortcuts let you right-click on a file and quickly get to Windows AI features like blurring the background of a photo, erasing objects, or even summarizing content from Office files.

Four image actions are currently being tested in the latest Dev Channel builds of Windows 11, including Bing visual search to find similar images on the web, the blur background and erase objects features found in the Photos app, and the remove background option in Paint.

Microsoft is unveiling its own command-line text editor at its Build conference today. Edit on Windows will be accessible by using “edit” in a command prompt, allowing developers to edit files within the command line. It’s part of several improvements aimed at bettering the Windows experience for developers.

Edit on Windows is an open-source project by Microsoft, and it enables developers to edit files directly in the command line, just like vim, without having to switch to another app or window. Edit is small and lightweight, at less than 250KB in size. All the menu options on Edit have key bindings, and you can open multiple files and switch between them using the ctrl + P shortcut. Microsoft has also added find and replace to Edit, as well as match case and regular expression support, as well. Edit also supports word wrapping.

A Microsoft employee disrupted the company’s Build developer conference in Seattle, Washington, this morning, protesting against the company’s cloud and AI contracts with the Israeli government. Microsoft CEO Satya Nadella had only been onstage for a matter of minutes before protesters started interrupting his speech, with one shouting, “Free Palestine!” Nadella continued his keynote, ignoring the protesters as they were escorted out of a hall inside the Seattle conference center.

Microsoft employee Joe Lopez, who has spent the past four years working as a firmware engineer on the company’s Azure hardware systems team, was one of the protesters who interrupted Nadella. He was also joined by a fired Google employee who was part last year’s sit-in protests against Google’s cloud contract with Israel.

Web developers will be able to start leveraging on-device AI in Microsoft’s Edge browser soon, using new APIs that can give their web apps access to Microsoft’s Phi-4-mini model, the company announced at its Build conference today. And Microsoft says the API will be cross-platform, so it sounds like these APIs will work with the Edge browser in macOS, as well.

The 3.8-billion-parameter Phi-4-mini is Microsoft’s latest small, on-device model, rolled out in February alongside the company’s larger Phi-4. With the new APIs, web developers will be able to add prompt boxes and offer writing assistance tools for text generation, summarizing, and editing. And within the next couple of months, Microsoft says it will also release a text translation API.

“So the 10,000-foot-level view is that we’ve had three big revolutions in personal computing.” That’s how Ramanathan V. Guha, a technical fellow at Microsoft, begins his explanation of what I had thought was a relatively minor AI announcement coming at this year’s Build developer conference. But Guha continues to make his case that what he has created — a new open protocol for the web called NLWeb — is actually an important part of something truly enormous.

Oh, the three revolutions: graphical user interfaces, the internet, mobile. Guha says we’re in the middle of the fourth, but doesn’t just chalk it all up to artificial intelligence. For him, the new revolution is “being able to communicate with applications, and computers in general, with free-form language.” He loves the trend, but not the way it’s shaping up. Too much of that new communication, Guha thinks, is mediated by products like ChatGPT, Claude, and yes, even Bing. He doesn’t like the idea that the web will be utterly consumed by chatbots, which take all their knowledge and return no value. And he thinks he knows how to fix it.

GitHub is launching an AI coding agent that can do things like fix bugs, add features, and improve documentation — all on a developer’s behalf. The agent is embedded directly into GitHub Copilot, and it will start working once a user assigns it a task, according to an announcement at Microsoft Build.

To complete its work, GitHub says the AI coding agent will automatically boot a virtual machine, clone the repository, and analyze the codebase. It also saves its changes as it works, while providing a rundown of its reasoning in session logs. When it’s finished, GitHub says the agent will tag you for review. Developers can then leave comments that the agent will automatically address.

Microsoft launched its Copilot Plus PC and Windows AI efforts last year, and now it’s going a step further today with native Model Context Protocol (MCP) in Windows and the launch of the Windows AI Foundry. The groundwork is necessary for a future envisioned by Microsoft whereby automated AI agents assist their human companions.

Introduced by Anthropic late last year, MCP is an open-source standard that’s often referred to as the “USB-C port of AI” apps. Just as USB-C connects devices from many manufacturers to a variety of peripherals, developers can use MCP to quickly let their AI apps or agents talk to other apps, web services, or now even parts of Windows. Microsoft’s embrace of this protocol is a big part of its ambitions to reshape Windows and make it ready for a world of AI agents to be able to connect to apps and services in ways that haven’t been possible before.

Microsoft is making its Windows Subsystem for Linux (WSL) open-source today, opening up the code for community members to contribute to. After launching WSL for Windows 10 nearly nine years ago, it has been a multiyear effort at Microsoft to open-source the feature that enables a Linux environment within Windows.

“It has been a consistent request from the developer community for some time now,” says Windows chief Pavan Davuluri in an interview with The Verge. “It took us a little bit of time, because we needed to refactor the operating system to allow WSL to live in a standalone capacity that then allowed us to open-source the project and be able to have developers go and make contributions and for us to ingest those into the Windows pipeline and ship it at scale.”

I reported in my Notepad newsletter earlier this month that Microsoft was getting ready to host Elon Musk’s Grok AI models, and now it’s official. At Microsoft’s Build developer conference today, the company confirmed it’s expanding its Azure AI Foundry models list to include Grok 3 and Grok 3 mini from xAI.

“These models will have all the service level agreements (SLAs) Azure customers expect from any Microsoft product,” says Microsoft. The Grok AI models will be hosted and billed directly by Microsoft, and offered to its own product teams and customers through its Azure AI Foundry service.

Microsoft’s annual developer conference kicks off today in Seattle, Washington, during the same week Google hosts its own I/O developer event in Mountain View, California. Build will be focused on Microsoft’s latest platform changes for developers, including new AI announcements that are bound to go head-to-head with Google’s own news.

Microsoft is streaming Build online free of charge and developers, students, and engineers will also be able to attend the in-person event at Seattle’s conference center. I’m expecting Microsoft to focus largely on AI this year, with emphasis on its push for AI agents that Microsoft envisions working alongside humans as digital colleagues.