Best Open Source Tools of June 2026

1. 1

   1. Skybridge

   575 upvotes

   The full-stack open source React framework for MCP Apps

   MCP apps are the new website: they're real, interactive apps that run right inside AI assistants like ChatGPT and Claude. The tooling to build them didn't exist, so we built it. Meet Skybridge, the React framework that handles the…

   #2 on June 22, 20261 maker
2. 2

   2. InsForge Backend Branching

   530 upvotes

   Git style branching for your backend

   Git-style branching for your entire backend. Spin off a branch to get a full, isolated copy of everything: your database, storage, auth, edge functions, and more, ready for your agents to experiment on without touching production.

   #2 on June 3, 20261 maker
3. 3

   3. superlog

   487 upvotes

   Make your product bug-free

   Superlog is an open-source autonomous observability tool. It installs itself and fixes the bugs it finds. With a single prompt, it instruments your repository with OpenTelemetry and keeps it up-to-date. When something breaks, it groups…

   #3 on June 3, 2026YC X261 maker
4. 4

   4. Novu Connect

   364 upvotes

   Ship agents where your users already work

   Novu Connect lets any AI agent have two-way conversations across Slack, Teams, WhatsApp, Telegram, and email without building each channel integration yourself. Bring your own agent logic, model, or code. Novu handles the communication…

   #1 on June 15, 20261 maker
5. 5

   5. Kimi K2.7 Code

   344 upvotes

   Kimi’s most capable coding model yet

   Kimi K2.7 Code is Moonshot AI’s latest coding-focused agentic model, built for long-horizon software engineering, 256K context, multi-step tool use, multimodal inputs, and around 30% lower reasoning-token usage than K2.6. Available in…

   #2 on June 13, 20261 maker
6. 6

   6. Google Gemma 4 12B

   304 upvotes

   Run multimodal AI locally with an encoder-free architecture

   Gemma 4 12B processes text, vision, and audio natively without separate encoders, running on 16GB VRAM. For developers building local agentic applications who need multimodal capability without cloud dependency.

   #4 on June 4, 20261 maker
7. 7

   7. Persona.js

   282 upvotes

   Add WebMCP-native AI chat to any Frontend

   Persona is a lightweight, open-source AI chat UI library that embeds into any website, from modern apps to static HTML. Unlike React-based chat frameworks, Persona is framework-free, backend-agnostic, and WebMCP-native, so your assistant…

   #3 on June 28, 20261 maker
8. 8

   8. Reframe

   250 upvotes

   Surf like it's 1999

   Reframe is an open-source browser based on Electron for macOS that brings back the look & feel of Safari 1.0, Netscape 4.8, Firefox 1.0 and Internet Explorer 5.0, with a built-in Wayback Mode.

   #2 on June 20, 20261 maker
9. 9

   9. PandaProbe Cloud

   242 upvotes

   Agent Engineering, Fully Managed.

   PandaProbe Cloud gives your team full-stack tracing, evals, and monitoring for agents with zero infrastructure to manage. Ship better agents without the ops overhead.

   #5 on June 15, 20261 maker
10. 10

    10. agmsg

    240 upvotes

    Stop copy-pasting between your AI coding agents

    Stop being the copy-paste relay between your AI coding agents. agmsg lets Claude Code, Codex, Gemini CLI, and Copilot CLI message each other directly through a shared SQLite database — no daemon, no network, no Python. Just bash +…

    #5 on June 9, 20261 maker
11. 11

    11. Hermes Desktop

    215 upvotes

    The agent that grows with you

    Hermes Desktop — the open-source agent that grows with you, now a native app for macOS, Windows, and Linux. By Nous Research.

    #6 on June 3, 2026hermesdesktop.app
12. 12

    12. PMB

    203 upvotes

    Stop re-explaining your project to AI coding agents

    PMB gives Claude Code, Cursor, Codex and Zed persistent project memory through MCP. It stores decisions, lessons, goals, recent work, project facts and docs in one SQLite workspace on your disk. No cloud, no API keys, no LLM call on the…

    #5 on June 29, 20261 maker
13. 13

    13. The Virtual OS Museum

    196 upvotes

    Relive vintage operating systems right on your desktop

    Over 1,700 pre-installed operating systems spanning 1948 to today, in a single Linux VM. Bundled QEMU, VirtualBox, and UTM. One-click launchers for Windows and Linux.

    #5 on June 8, 2026
14. 14

    14. Mellum by JetBrains

    194 upvotes

    Fast LLMs for low-latency and high-performance workflows

    Meet Mellum, a family of fast language models, including a next-generation model for ultra-low-latency and high-performance inference.

    #4 on June 20, 2026
15. 15

    15. Hush

    188 upvotes

    Open-source noise suppression for voice AI agents

    Hush removes competing voices, background noise, and audio interference from real-time calls so your voice AI agents always hear what matters.

    #6 on June 23, 20261 maker
16. 16

    16. NTSC-RS

    165 upvotes

    Open-source video emulation of analog TV and VHS artifacts

    ntsc-rs is a free, open-source VHS and analog TV video effect. Use it online in your browser, as a standalone application, or as a plugin for DaVinci Resolve, After Effects, and more.

    #7 on June 8, 2026
17. 17

    17. Open Caffeine

    161 upvotes

    Keep your Mac awake

    Open Caffeine is a native macOS menu bar app for keeping your Mac awake for a chosen duration. Pick presets, set a custom timer, toggle screen sleep behavior, use a global hotkey, show a countdown in the menu bar, and stop automatically…

    #10 on June 1, 20261 maker
18. 18

    18. PawPause

    148 upvotes

    Lock your keyboard and prevent cats from causing chaos

    A tiny macOS menu bar app that detects when your cat is on the keyboard and pauses input system-wide. 100% on-device. Open source. Free.

    #7 on June 2, 20261 maker
19. 19

    19. Sipcode

    136 upvotes

    Keep Claude Code's context clean for sharper answers

    Context hygiene for Claude Code. Caps verbose tool output and dedupes same-session re-reads so the model sees signal, not noise. Anthropic measures 29% quality lift from cleaner context. Proof: 62.6% median tool-output savings on a locked…

    #12 on June 23, 20261 maker
20. 20

    20. MindReader v1

    135 upvotes

    Read minds (simulated fMRI data, channeled to neuro-metrics)

    How do you feel? It is the oldest question in art and the newest one we can answer in technology. MindReader takes your content and simulates, region by region, how a brain responds to it. Completely Open Source - we encourage you to…

    #9 on June 16, 20261 maker
21. 21

    21. Conduit

    129 upvotes

    Fix the tool-list bloat slowing your AI agent

    Your agent got slower the more MCP servers you added, and it's not the model. Every server dumps its whole tool list into context on every request: 3 servers cost ~24k tokens before you even say hi. Conduit puts them behind one local…

    #13 on June 23, 2026YC W24conduit.ai1 maker
22. 22

    22. Keen Code

    126 upvotes

    A context-efficient CLI coding agent built by agents

    Keen Code is an open-source, context-aware and efficient CLI coding agent written in Go. Three aspects stand it out from other similar products: - It was built from scratch by coding agents, with the full prompt/design trail preserved and…

    #11 on June 4, 20261 maker
23. 23

    23. LocalClicky

    125 upvotes

    Control your Mac with your voice locally

    LocalClicky is a Mac menubar app that lets you have a real conversation with your computer - completely offline. Say "Computer" to start a session. It stays listening. You chain commands back to back. Say "goodbye" when you're done.…

    #9 on June 5, 20261 maker
24. 24

    24. MiMo Code

    116 upvotes

    A coding agent with explicit long-term memory architecture

    MiMo Code is an open-source terminal AI coding agent built on OpenCode. Optimized for long-horizon tasks, it uses an independent checkpoint subagent to manage unbounded context windows, executes sandbox workflows, and evolves via…

    #14 on June 15, 2026
25. 25

    25. Deep Work Plan

    114 upvotes

    Models matter. Context matters more. Give your agent a plan.

    Deep Work Plan turns any repo into a harness with the context of your best engineer — so any AI agent codes like your smartest model and can't drift from the plan. Not a chat window it forgets, a spec written into the repo: atomic tasks…

    #8 on June 17, 2026deepworkplan.com1 maker

Junior imports every day's Product Hunt leaderboard. Each launch is filed under the first topic its makers chose, so it appears in one category only. This list takes the Open Source launches dated in June 2026 and ranks them by their upvotes. It refreshes daily.

• Best Productivity Tools252
• Best Design Tools77
• Best Developer Tools63
• Best Mac Apps52
• Best Android Apps48
• Best Marketing Tools40
• Best AI Tools30
• Best SaaS Tools36
• Best iOS Apps47
• Best APIs43
• Best Chrome Extensions38
• Best Analytics Tools17
• Best Health & Fitness Apps30
• Best Social Media Tools21
• Best Sales Tools17
• Best Fintech Tools26

• All Open Source Tools732
• Every launch in June 2026
• All best-of lists

What was the top Open Source launch of June 2026?

Skybridge ("The full-stack open source React framework for MCP Apps"), with 575 upvotes on June 22, 2026, where it finished #2 of the day.

How many Open Source Tools launched in June 2026?

74 on Product Hunt, with 7,445 upvotes between them. This list shows the 25 most upvoted.

How is this list ranked?

By Product Hunt upvotes, as recorded on launch day. Ties go to the launch with the better daily rank. Every launch is counted once, in the category its makers listed first.

How do I reach the makers of these Open Source Tools?

Each launch links to its page on Junior, with the people behind it (20 makers across this list). Junior adds their verified work emails, LinkedIn and X profiles for subscribers.