.NET 11 Preview 5 is now available! - The big monthly drop. Highlights include Blazor SSR client-side validation, QuickGrid without interactivity, and a Blazor WebAssembly Gateway; C# 15 union declarations/patterns and closed class hierarchies; System.Text.Json JSON Lines (NDJSON) support; LINQ full outer joins; and X25519 key agreement.

Blog post: "Discriminated unions in C# and .NET 11 (for real this time)" - A great companion read to the above - Maarten Balliauw digs into what the native union types and exhaustive pattern matching landing in C# actually look like in practice.

.NET 8 and .NET 9 will reach End of Support on November 10, 2026 - Worth planning around: both .NET 8 (LTS) and .NET 9 (STS) hit end of support on the same date, with no further security updates after that.

Our Latest Aspirations - the Aspire 2026-2027 Roadmap - The Aspire team laid out their directional roadmap around three pillars: making Aspire "agent-ready" for agentic workflows, scaling with your team, and being "built to ship" with stronger release foundations. On the wishlist: live AppHost reloading, multi-repo support, richer testing across all languages, expanded polyglot support (Python/Go/Rust), GitLab pipeline generation, better Kubernetes deployment, and first-class Entra ID auth. They also shared a cracking year - 31 releases, 2,277 issues closed, and 6k GitHub stars.

AI-Powered MSBuild Investigation with the Microsoft Binlog MCP Server - A new (preview) MCP server that parses your .binlog files and exposes ~15 tools, so Copilot/agents can actually answer "why did my build fail?" or "why is it so slow?". Ships via a dotnet-msbuild plugin that Copilot agent mode auto-discovers.

SkiaSharp 4.0 - the first stable release - First stable v4 of the hugely popular cross-platform 2D graphics library (it underpins rendering in MAUI, Avalonia, Uno, and more), with an updated Skia engine, variable-font support, and up to ~24% faster rendering.

Metalama 2026.1 GA - PostSharp's successor metaprogramming/AOP framework hits its first LTS release, with complete C# 14 support and a redesigned Redis backend.

Introducing Uno Platform Studio 3.0 - A major release of the cross-platform .NET UI toolkit's studio, pairing an AI agent with the browser-based Studio App builder.

JetBrains had a busy month for .NET devs...

Claude Fable 5 and Claude Mythos 5 - A brand-new flagship model line from Anthropic, with always-on adaptive thinking, 1M-token context, and 128K output. Fable 5 is the widely-released frontier model; Mythos 5 is the limited-availability Glasswing variant. Then, just three days later, Anthropic had to suspend access to both following a US government export-control directive. *Update:** on June 30 the export controls were lifted and Fable 5 is being redeployed, relaunching globally on July 1. Anthropic shipped an improved safety classifier that blocks the vulnerability-finding jailbreak (discovered by Amazon researchers) that had spooked the government, and Mythos 5 is being restored for approved US organisations too.

Introducing Claude Sonnet 5 - As well as Fable 5, Anthropic released Sonnet 5, which is a solid step up from Sonnet 4.6, with near-Opus-4.8 agentic performance (planning, browser/terminal tool use, autonomous multi-step work) and a lower prompt-injection rate. It's the default model on Free/Pro, and rolling out fast across API, Bedrock, Vertex, Microsoft Foundry, VS Code, GitHub Copilot, Cursor, and OpenRouter. Introductory pricing is $2/$10 per million tokens through Aug 31 (then $3/$15). Claude Code already defaults to it, with a native 1M-token context.

Previewing GPT-5.6 "Sol" - OpenAI's next-generation line: GPT-5.6 Sol (flagship), Terra (balanced), and Luna (fast/cheap). Sol adds a new max-reasoning effort and an "ultra" sub-agent mode, and sets a new SOTA on Terminal-Bench 2.1. Interestingly - and just like Anthropic above - it launched only to ~20 government-approved partners. Sol is priced at $5/$30 per 1M input/output tokens.

The open-weight models are really closing in on the frontier - three landed this month, all with 1M-token context and aimed squarely at long-horizon agentic coding...

Claude in Microsoft Foundry is now generally available - Claude (Opus 4.8 + Haiku 4.5 via the Messages API) is now GA natively in Microsoft Foundry on Azure, with Entra ID auth, Azure RBAC/governance, and an optional US data zone.

Microsoft Copilot Cowork is now generally available - Microsoft's agentic workplace tool goes GA worldwide to all Microsoft 365 Copilot license holders, adding new models, browser use, and consumption billing. It runs on Anthropic models (Opus 4.8, Sonnet 4.6) at launch, with a "Cowork 1" model coming - and Microsoft claims it's 30-40% cheaper per prompt than Claude Cowork.

Introducing Claude Tag - A beta Slack integration: tag @Claude into a channel to delegate tasks and connect tools, data, and codebases, with context memory, proactive updates, and async task handling (Team/Enterprise).

Claude Code now supports artifacts - Claude Code can turn session work into live, shareable web pages - PR walkthroughs, system explainers, dashboards, release checklists - built from the full session context, and private to your org by default (beta, Team/Enterprise).

SpaceX to acquire Cursor for $60B - SpaceX exercised its April option to buy Anysphere (makers of Cursor) all-in-stock at a ~$60B equity value, just four days after its record IPO, folding it into its xAI/Grok AI division. Cursor's ARR reportedly went from ~$100M in early 2025 to over $4B by June 2026.

Cursor Mobile App for iOS - Cursor for iPhone/iPad is now in public beta on all paid plans: launch and manage cloud agents, remote-control a desktop agent, get Live Activities and push notifications, and review diffs / merge PRs.

GitHub Desktop 3.6: Worktrees and deeper Copilot integration - Git worktree support, plus Copilot now powering commit-message authoring and merge-conflict resolution (honouring your copilot-instructions.md / AGENTS.md).

Visual Studio Code 1.126 - Multiple parallel chats per agent session sharing one working context, session-level cost transparency (the whole-session credit cost, not just per-turn), and a unified model-customization picker.

Execution context for GitHub Copilot in SSMS - SQL Server Management Studio now lets you set a specific database user / SQL login for Copilot-executed queries, so the agent runs under controlled permissions.

Announcing TypeScript 7.0 RC - The native (Go-based) TypeScript compiler port reaches Release Candidate, with roughly 10x faster type-checking and unchanged semantics. One of the most-anticipated toolchain milestones of the year - stable GA is expected about a month later.

Upcoming breaking changes for npm v12 - npm v12 (shipping July 2026) flips three defaults to opt-in: lifecycle install scripts won't run without npm approve-scripts, and Git / remote-URL / tarball dependencies won't resolve without --allow-git / --allow-remote. A welcome (if disruptive) hardening of the default npm install trust model.

Open VSX 1.0.0 - The vendor-neutral VS Code extension registry (600M+ downloads/month) hits 1.0. It's the backbone for all the VS Code forks - Cursor, Windsurf, VSCodium, and the like.

Supply-chain attacks - the npm/PyPI worm wave (the "Mini Shai-Hulud" / Miasma / Hades campaign family) rolled on through June. In most cases the malicious versions have since been pulled (though some are reportedly still live) - either way, audit your lockfiles and update...

one-at-a-time: Quite often an AI's response can be a wall of text. This skill tells the agent to just ask me one question at a time, or give me one piece of information at a time. It makes it much easier to digest and respond to.

teach-me: AI's not just amazing at doing things for you, but also at teaching you. This skill tells the agent to teach you about whatever you're talking about, one step/level at a time. It'll give you the opportunity to ask questions as you go.