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Online compiler for many languages, including MySQL

Agentmemory
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Stop re-explaining your project to Claude every session. ContextForge adds persistent memory to Claude Code, Cursor, and Copilot via MCP. Free tier, 3-minute setup.

Which is more popular?
Based on our record, Rextester should be more popular than ContextForge.dev. It has been mentioned 7 times since March 2021.
Website, pricing, platforms and company facts side by side.
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Rextester
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| Website | insurance.rextester.com | contextforge.dev |
| Pricing | — | |
| Platforms | — | |
| Company | — | Startup from the United States · 2026 |
| Listed in |
In their own words, as submitted to SaaSHub.

No description of Rextester yet.
ContextForge is persistent, searchable memory for AI coding agents — built on the Model Context Protocol (MCP). Your AI assistant forgets everything when the session ends. ContextForge fixes that: save architectural decisions, naming conventions, and debugging context once, and any MCP client...
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How to Make Claude Run Automated Workflows (ContextForge Skills Tutorial)
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How often each product is chosen within a category, 0–100% relative to the other.

As answered by people managing Rextester and ContextForge.dev.
ContextForge.dev's answer:
ContextForge is memory that lives at the MCP layer, so it works across every AI coding agent at once — Claude Code, Cursor, GitHub Copilot, ChatGPT, and Windsurf — not just one. Save a decision once and any client recalls it later with semantic search. It goes beyond a note store: automatic git sync turns your commits and PRs into searchable knowledge, plus task tracking, snapshots, and team sharing — all through a single MCP server you add with one command.
ContextForge.dev's answer:
Most memory tools are tied to a single agent or are just a key-value store. ContextForge is MCP-native, so it's portable across all your AI tools; it adds git sync so your codebase history becomes searchable context automatically; and it includes team features (shared spaces, collaborators) that solo-memory tools lack. Setup is one command, there's a genuine free-forever tier with no credit card, and paid plans start at just $9/month.
ContextForge.dev's answer:
Software developers and engineering teams who use AI coding assistants — Claude Code, Cursor, GitHub Copilot, ChatGPT, Windsurf — and are tired of re-explaining their project, architecture, and conventions every session. It fits solo developers working across multiple projects as well as small teams that need shared, persistent context.
ContextForge.dev's answer:
ContextForge was born from a simple frustration: AI coding agents forget everything the moment a session ends. Every new conversation meant re-explaining the same architecture, naming conventions, and past decisions. ContextForge was built to give AI agents a permanent, searchable memory through the Model Context Protocol — so knowledge is captured once and reused forever, across sessions and projects. It even dogfoods its own memory to help build itself.
ContextForge.dev's answer:
Next.js 16 (App Router), React and Tailwind CSS for the dashboard, hosted on Vercel. Supabase (PostgreSQL) with pgvector powers the semantic vector search, and Deno edge functions serve the API. Embeddings use OpenAI text-embedding-3-small. The MCP client is a Node.js package (contextforge-mcp) on npm, implementing the Model Context Protocol.
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External articles and on-site reviews we used to compare the two products.

It supports around 30 languages including Java, but it is more popular among C# users. Rextester started as a Regular Expression Tester, later grew to be an online IDE.
We have no reviews of ContextForge.dev yet. Be the first one to post
Recommendations tracked on public social media and blogs since March 2021.

My Professor has not provided any resources or material to help complete this project, I have tried to problem solve, use the internet, even chatgpt. (I can send the code that it gave me in comments if needed, but ) I need help... Source: over 3 years ago
Does it really do that? (I've just tried in rextester.com, it complains about declared but unused variables.). Source: almost 4 years ago
(A quick survey of some of the languages at rextester.com showed that they are usually counted from 1. I'd suggest doing the same would be least surprising.). Source: over 4 years ago
Init links the folder to a project, so every agent working in that repo reads and writes the same memory, and it adds the rules that make sessions check who else is live before big changes. For Cursor, Copilot, Claude Desktop and... - Source: dev.to / 17 days ago
I built ContextForge because I was losing this argument with my own agents several times a week. The idea is small: when we decide something, the agent saves the decision with the reason, in the project's memory. The next session, in... - Source: dev.to / about 1 month ago
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