frontpage.
newsnewestaskshowjobs

Made with ♥ by @iamnishanth

Open Source @Github

fp.

Show HN: Circuit Artist – Circuit simulator with propagation animation, rewind

https://github.com/lets-all-be-stupid-forever/circuit-artist
36•rafinha•4d ago•1 comments

Show HN: Terminal UI for AWS

https://github.com/huseyinbabal/taws
331•huseyinbabal•16h ago•172 comments

Show HN: An interactive guide to how browsers work

https://howbrowserswork.com/
247•krasun•21h ago•34 comments

Show HN: The bedtime – Another little bedside clock I made

https://www.stavros.io/posts/i-made-another-little-bedside-clock/
10•stavros•1h ago•6 comments

Show HN: An LLM-Powered PCB Schematic Checker (Major Update)

https://traceformer.io/
46•wafflesfreak•14h ago•18 comments

Show HN: Hover – IDE style hover documentation on any webpage

https://github.com/Sampsoon/hover
49•sampsonj•17h ago•20 comments

Show HN: I used AI to recreate a $4000 piece of audio hardware as a plugin

144•johnwheeler•2d ago•99 comments

Show HN: Quantum Tunnel

https://chuanqisun.github.io/quantum-tunnel/
28•osmoscraft•13h ago•12 comments

Show HN: Replacing my OS process scheduler with an LLM

https://github.com/mprajyothreddy/brainkernel
73•ImPrajyoth•5d ago•41 comments

Show HN: Claude Reflect – Auto-turn Claude corrections into project config

https://github.com/BayramAnnakov/claude-reflect
73•Bayram•1d ago•26 comments

Show HN: H-1B Salary Data Explorer

24•zuhayeer•14h ago•9 comments

Show HN: Living Memory Dynamics – "living" episodic memory embedding space

https://github.com/mordiaky/LMD
3•Mordiaky•6h ago•0 comments

Show HN: Offline tiles and routing and geocoding in one Docker Compose stack

https://www.corviont.com/
97•packet_mover•1d ago•37 comments

Show HN: Magic CSV – Transform CSVs with plain English, no formulas

https://magiccsv.app/
16•bored-developer•5d ago•2 comments

Show HN: Website that plays the lottery every second

https://lotteryeverysecond.lffl.me/
257•Loeffelmann•2d ago•140 comments

Show HN: I made R/place for LLMs

https://art.heimdal.dev
8•ekvanox•16h ago•1 comments

Show HN: CloudSlash – Find AWS waste and generate Terraform state rm commands

2•drskyle•9h ago•0 comments

Show HN: uvx ptn, scan a QR, get a terminal in your phone

https://github.com/lyehe/porterminal
98•yxl448•2d ago•42 comments

Show HN: Vho – AST-based analysis for better AI refactoring of large codebases

https://vue-hook-optimizer.vercel.app/
4•huali•10h ago•1 comments

Show HN: Remember Me – O(1) Client-Side Memory (40x cheaper than Vector DBs)

https://github.com/merchantmoh-debug/Remember-Me-AI
3•MohskiBroskiAI•16h ago•4 comments

Show HN: I built an HTTP/2 server in C++ to learn the protocol and language

https://github.com/rhargreaves/ion
8•kiyouta•1d ago•0 comments

Show HN: Use Claude Code to Query 600 GB Indexes over Hacker News, ArXiv, etc.

https://exopriors.com/scry
394•Xyra•5d ago•140 comments

Show HN: Krowdovi – Video-based indoor navigation on a DePIN creator economy

https://github.com/daftpixie/krowdovi
9•24hrmvp•1d ago•27 comments

Show HN: I built an international calling platform for the past 6 months

https://voklit.com
36•ahmgeek•1d ago•39 comments

Show HN: Get a brief before every meeting (open-source)

https://www.briefmymeeting.com
5•elieskilled•16h ago•0 comments

Show HN: Til.re – The URL is your timer, no signup required

https://til.re
15•iamlin•1d ago•7 comments

Show HN: OpenWorkers – Self-hosted Cloudflare workers in Rust

https://openworkers.com/introducing-openworkers
499•max_lt•3d ago•156 comments

Show HN: Calgebra – Set algebra for calendars in Python

https://github.com/ashenfad/calgebra
4•ashenfad•18h ago•2 comments

Show HN: Enroll, a tool to reverse-engineer servers into Ansible config mgmt

https://enroll.sh
263•_mig5•4d ago•55 comments

Show HN: BusterMQ, Thread-per-core NATS server in Zig with io_uring

https://bustermq.sh/
134•jbaptiste•4d ago•69 comments
Open in hackernews

Show HN: Fahmatrix – A Lightweight, Pandas-Like DataFrame Library for Java

https://github.com/moustafa-nasr/fahmatrix
46•mousomashakel•7mo ago
Hey HN, I’ve built Fahmatrix, a minimal, fast Java library for working with tabular data — inspired by Python’s pandas, but designed for performance and simplicity on the JVM.

After working extensively with Python’s data stack, I often ran into limitations related to speed, especially in larger or long-running data workflows. So I built Fahmatrix from scratch to offer similar APIs for manipulating CSVs, performing summary statistics, slicing rows/columns, and more — but all in Java.

Features:

Lightweight and dependency-free

CSV/TSV import with auto-headers

Series/DataFrame structures (like pandas)

describe(), mean(), stdDev(), percentile() and more

Fast parallel operations on numeric columns

Java 17+ support

Docs: https://moustafa-nasr.github.io/Fahmatrix/ GitHub: https://github.com/moustafa-nasr/fahmatrix

I’d love feedback from the Java and data communities — especially if you’ve ever wanted a simple dataframe utility in Java without needing full-scale ML libraries.

Happy to answer any questions!

Comments

rickette•7mo ago
Congrats on putting this out there. There isn't a de facto pandas-like library in Java like you said. But for Kotlin there is: https://github.com/Kotlin/dataframe
mousomashakel•7mo ago
Thanks so much! Yep, I’ve seen the Kotlin DataFrame lib — very elegant. Fahmatrix is meant for plain Java users who want similar capabilities without switching ecosystems. Appreciate the support!
uwemaurer•7mo ago
Always great to see efforts to make working with data frames easier. Here are some similar data frame libraries for Java:

https://github.com/jtablesaw/tablesaw

https://github.com/dflib/dflib

My preferred way is just use duckdb java API. I didn't see anything better in performance/efficiency. Also a SQL query is often easier to write

theanonymousone•7mo ago
Yes. It has bothered me for a long time too. Maybe the best mix is a dataframe library with basic operations (column select, non-null etc), which also allows SQL for more complex stuff?
radus•7mo ago
Polars and duckdb interoperate nicely and can enable this flexibility
theanonymousone•7mo ago
Does Polars have a Java library?
mousomashakel•7mo ago
Totally agree that SQL can be the best tool for many jobs. My goal with Fahmatrix is to serve the opposite niche: where devs want something that's Java-native, procedural, and simple without reaching for an external engine. SQL support or DSL might come later though — I see the appeal.
theanonymousone•7mo ago
Sure. So maybe notehr comment would be to make it (particularly the Series class), as compatible with Java Streams as possible.

Next step would likely be compatibility with popular libraries such as Apache Commons Math: https://commons.apache.org/proper/commons-math/userguide/sta...

mousomashakel•7mo ago
Thanks! I'm aware of those great projects. Fahmatrix aims to offer a lightweight, dependency-free alternative that’s easy to embed in any Java app. DuckDB is super impressive, especially for SQL-heavy tasks — but my goal is more about a native, fluent API for those who prefer direct Java code over SQL.
skanga•7mo ago
What about Tablesaw, Apache Arrow? How does this compare ...
mousomashakel•7mo ago
Good question. I’ll publish benchmarks soon, but the core difference is that Fahmatrix is fully Java, no JNI, and minimalistic — ideal for small projects or environments like Android. Tablesaw and Arrow are more powerful, but heavier. Fahmatrix aims to be the “just enough” middle ground.
owlstuffing•7mo ago
Nice!

I’m currently using manifold-sql with duckdb for this.

mousomashakel•7mo ago
Thanks! That’s a great combo — manifold-sql + duckdb gives you strong typing with powerful SQL under the hood. Fahmatrix is aiming to complement that approach for cases where you want quick, native Java code without SQL — e.g., when building data flows or custom logic inline. Would love to hear if you’ve hit any pain points that a Java-native approach could help with.