Top 10 Open-Source Picks: September 23
A curated look at the 10 open-source repositories that dominated developer attention on Wednesday, September 23, 2026. From trending newcomers to steadily-growing community favorites, here is what mattered most.
dream-num/univer
The Office Harness for AI Agents — Spreadsheets, Docs, Slides, Canvas, Relational Tables, and PDF in one runtime.
davila7/claude-code-templates
CLI tool for configuring and monitoring Claude Code
superdesigndev/treg
OpenRouter for agent tools. Join community here: https://discord.gg/6mQYYfFMAn
keepassxreboot/keepassxc
A cross-platform password manager with encrypted local databases
DefinitelyTyped/DefinitelyTyped
The repository for high quality TypeScript type definitions.
AvaloniaUI/Avalonia
Develop Desktop, Embedded, Mobile and WebAssembly apps with C# and XAML. The future of .NET UI
Editor's Takeaway
On September 23, 2026, these 10 repositories captured the attention of developers worldwide. Leading the charge were substrate, univer, claude-code-templates alongside 7 other compelling projects, with each representing a different facet of where open-source momentum is heading. What ties them together is community trust: high star counts, active contributors, and real-world utility. If you haven't already, explore each project on its detail page, check out the contributor leaderboard, and consider starring the ones that solve problems you care about. Open source thrives when people engage, and these 10 repos are the proof.