Jarsurgeon – Instrument and rebuild Java programs without source

In plain words

Jarsurgeon is a developer tool that allows users to instrument and rebuild Java programs without access to the original source code. It enables modifications to compiled Java applications by working directly with JAR files. The tool is useful for developers who need to add instrumentation, debugging capabilities, or make changes to Java programs when source code is unavailable.

written from the facts on this page · September 2026

• AW
  A web debugger an ex-Cloudflare team has been working on for 4 years2024 · ▲886

  Hey HN, I wanted to show you a product a small team and I have been working on for 4 years. https://jam.dev It’s called Jam and it prevents product managers (like I used to be) from being able to create vague and un-reproducible bug tickets (like I used to create). It’s actually really hard as a non-engineer to file useful bug tickets for engineers. Like, sometimes I thought I included a screenshot, but the important information the engineer needed was what was actually right outside the boundary of the screenshot I took. Or I'd write that something "didn't work" but the engineer…

• 
  Tabstack Dev ToolsJun 2026 · tabstack.ai · ▲319

  Ditch your scraper. Make one API call with any tool.

• 
  Jestor2021 · jestor.com · ▲192

  No-code internal tool builder to scale startup operations

• 
  Jar.tools – View, Change, Decompile Java Jar Files2025 · jar.tools · ▲9

  JAR Tools is your all-in-one online solution to effortlessly view, edit, and decompile Java JAR files directly in your browser. No installation required

• 
  Java Decompiler Online2023 · ▲69

  Convert class files to Java source files

• 
  Java 7 Features Backported to Android2013 · github.com · ▲49

  Java 7 features backported to Android 2.2+. Contribute to yareally/Java7-on-Android development by creating an account on GitHub.

• 
  /dev/null▲483

  a social network for devs

  Dev tools · 3d ago · dev-null.sh

• 
  Whiteboard (YC W26) – an open-source IDE for thoughtful software design▲423

  open-source IDE for thoughtful software design. Contribute to devdotfast/whiteboard development by creating an account on GitHub.

  Dev tools · 27d ago · github.com

• 
  Reladraw – A diagram language where you decide where to place things▲411

  Contribute to reladraw/reladraw development by creating an account on GitHub.

  Dev tools · 25d ago · github.com

• 
  OpenBot▲362

  Grok Bot alternative: free, local, open-source, multiplayer

  Dev tools · 23d ago · openbot.run

• 
  Talanoa▲345

  Hi HN, I’m a fullstack developer, and honestly, I’ve lost count of how many side projects I’ve worked on over the years. But one idea kept coming back to me: a different kind of email client. It first came to me in 2014: “What if we could handle emails more like conversations?” Every year, I’d revisit this concept in my “Build Notes.” Ten years later, no one had built exactly what I had in mind — so I finally decided to do it myself. That’s how Talanoa was born. I wanted something focused on people, not timelines. I was tired of marking messages as unread just to remember to reply later, or…

  Dev tools · 20d ago · talanoa.email

• 
  CoreSpeed▲332

  One MCP for everything your agents need: apps, memory, tools

  Dev tools · 28d ago · corespeed.io

• 
  Apple Watch▲616

  The most personal device Apple has ever created

  Life & fun · 2014 · apple.com

• 
  Zero To One▲615

  Peter Thiel's new book on Startups

  Life & fun · 2014 · amazon.sg

• 
  ReadMe▲601

  Beautiful Documentation Made Easy

  Life & fun · 2014 · readme.com

• 
  Forest▲533

  Put down your phone and stay focused. Or a tree will die. 🌳😵

  Life & fun · 2014 · forestapp.cc

• 
  Spectacle▲458

  Move and resize windows with ease on Mac.

  Life & fun · 2014 · spectacleapp.com

• 
  iPhone 6▲397

  Bigger, better iPhone

  Life & fun · 2014 · apple.com