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Show HN: OpenTIE and OpenXWA, Modern Ports of Tie Fighter and X-Wing Alliance

https://github.com/elyosh/OpenTIE/
97•elyosh•5h ago•21 comments

Show HN: We built open OpenRouter that turns usage into a better model

https://github.com/experientiallabs/experiential
131•SilenN•6h ago•22 comments

Show HN: The load-bearing vocabulary of Claude

https://louisabraham.github.io/load-bearing/
391•Labo333•19h ago•184 comments

Show HN: IndexFlow – Open-source indexing infrastructure built with Rust

https://github.com/IndexFlowing/IndexFlow-core
6•mandarinclips•1h ago•2 comments

Show HN: Voronoi Go

https://voronoigo.com/
100•igpay•9h ago•13 comments

Show HN: A lightweight, stateless database for agent memory

https://polign.com/blog-edge-agent-memory
27•anuptalwalkar•1d ago•10 comments

Show HN: Restoredrill – proves your Postgres backups restore

https://github.com/ahmadpiran/restoredrill
44•ahmadpiran•13h ago•21 comments

Show HN: A public feed of website changes

https://app.monity.ai/public/feed
3•kamilms21•2h ago•0 comments

Show HN: Leadcode – per-client account isolation for Claude Code, Codex, and gh

https://leadcode.build/
3•gsbecerrag•2h ago•0 comments

Show HN: Lightweight reimplementation of YaCy peer as small Go services

https://github.com/nikitakarpei/my-yacy-node
2•nikitakarpei•3h ago•0 comments

Show HN: RealDiff – runtime behavior diffing for pull requests (six languages)

https://github.com/issacnitin/RealDiff
38•issacnitin•14h ago•7 comments

Show HN: My Claude quota ran out in 10 minutes, so I made a tool to find out why

https://github.com/kelviq/tare
70•sachinneravath•11h ago•53 comments

Show HN: Caravan, a flexible TypeScript-first logger for JavaScript applications

https://github.com/carlos-menezes/caravan
5•carlos-menezes•3h ago•0 comments

Show HN: Yet another minimal and lightweight terminal multiplexer written in Go.

https://github.com/patriceckhart/hrdx
32•patriceckhart•10h ago•13 comments

Show HN: L0/L1/L2 agents, leases, gates, audits, Git-worktree isolation

https://github.com/alex-reysa/singular-lite
4•mr-pickle•5h ago•0 comments

Show HN: Proval – Self-hosted code review agent for GitLab, Forgejo, and GitHub

https://github.com/seoes/proval
9•dowonseo•13h ago•1 comments

Show HN: Beating GPT5.5-xhigh for Coding agent security with SLMs and IRM

https://harden.run/blog/aif-research-and-evidence
6•se4u•5h ago•3 comments

Show HN: A Windows 98 retro voting tug-O-war system

https://www.imright.wtf
3•Dubbo1•7h ago•1 comments

Show HN: A private radio station for issue updates across your org

https://github.com/statemediafm/statemediafmradio
5•private4e584d•10h ago•0 comments

Show HN: Buslens – where can I get to by bus? (UK)

https://rupertlinacre.com/buslens/
81•RobinL•1d ago•55 comments

Show HN: We built the smallest dual-band aircraft tracker

https://pantsforbirds.com/the-worlds-smallest-dual-band-ads-b-receiver-module/
36•CoolNamesAllTkn•1d ago•7 comments

Show HN: go-binsync – Go binary patches up to 67× smaller than bsdiff

https://github.com/wjordan/go-binsync
5•wgjordan•8h ago•0 comments

Show HN: LatticeDB – Like SQLite but for graph databases

https://github.com/jeffhajewski/latticedb
182•smiths1999•2d ago•53 comments

Show HN: OpenWand – A mission to remove chat interface from working with AI

https://github.com/SunnyLich/OpenWand
3•OpenWand•8h ago•0 comments

Show HN: Z, minimal agentic harness for engineers that just works

https://github.com/computerex/z
2•computerex•9h ago•0 comments

Show HN: Collaborate with your team on Claude and ChatGPT artifacts

https://www.valet.dev/blog/your-agent-is-only-the-first-collaborator
5•miradu•9h ago•0 comments

Show HN: Interactive SDP Explainer for WebRTC, Sip, and RTSP

https://explainer.pion.ly/
5•JoTurk•9h ago•1 comments

Show HN: Music Visualizer|New MilkDrop engine and various types of reactive art

https://ikandy.app/
4•IKANDYAPP•9h ago•1 comments

Show HN: Build your own theme park

https://www.magicpatterns.com/theme-park
51•thealexanderlee•1d ago•23 comments

Show HN: Sparrow-2 – Solving the cocktail party problem

https://www.tavus.io/blog/sparrow-2
8•code_brian•10h ago•1 comments
Open in hackernews

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

https://github.com/moustafa-nasr/fahmatrix
46•mousomashakel•1y 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•1y 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•1y 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•1y 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•1y 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•1y ago
Polars and duckdb interoperate nicely and can enable this flexibility
theanonymousone•1y ago
Does Polars have a Java library?
mousomashakel•1y 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.
skanga•1y ago
What about Tablesaw, Apache Arrow? How does this compare ...
mousomashakel•1y 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•1y ago
Nice!

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

mousomashakel•1y 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.
theanonymousone
•
1y 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•1y 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.