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Show HN: Coldframe, a honeypot that poses as a supermarket fridge controller

https://github.com/hedgerow-dev/coldframe
228•hedgerow-dev•15h ago•54 comments

Show HN: Maple – Sub-2-BPW Moe Pruning to Run Gemma 4 26B at 45 TPS on a 6GB GPU

https://github.com/AmSach/maple
7•AmSach•4h ago•3 comments

Show HN: Where Were We

https://wherewerewe.app/
42•zkiihne•11h ago•16 comments

Show HN: An offline desktop companion to help maintain a healthy blink rhythm

https://eyesrhythm.com/
31•prnysoni•10h ago•15 comments

Show HN: LLM weight editing tool made by a 15-year-old

https://github.com/Miyamoto-Renya/LaplacesScissors
6•032renya•6h ago•0 comments

Show HN: We compressed a 31B video+audio diffusion model to 14B, 6 steps, INT8

https://github.com/Video-Rebirth/hyperflow-h3-flash
66•jiant•17h ago•13 comments

Show HN: Spindle – a full-featured, type-safe web framework for OCaml 5

https://github.com/hyphatech/spindle
59•zaiev•2d ago•8 comments

Show HN: Green tests are not proof – verifier for C/C++ and firmware fixes

https://unfix.dev/
15•u-pump•2d ago•1 comments

Show HN: Reges Town – a 3D city run by AI citizens, in the browser

https://regestown.com
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Show HN: Waymark – A workflow engine that compiles jobs instead of replaying

https://github.com/piercefreeman/waymark
81•icyfox•2d ago•45 comments

Show HN: Tmux-restore saves tmux windows and agent sessions across reboots

https://github.com/andrewboldi/tmux-restore
58•boldi•4d ago•36 comments

Show HN: I declared war on every country, one at a time. 77 of 133 survived

https://playgod.earth/every-country-vs-the-world
3•kyleclouthier•8h ago•0 comments

Show HN: Levithas

https://levithas.app
2•monidp•11h ago•0 comments

Show HN: Logo Deal – Logos anyone can edit with text

https://logo.deal/
9•vednig•19h ago•3 comments

Show HN: A decent text-to-image model trained for ~$20K (Apache 2.0 Weights)

https://www.linum.ai/field-notes/pjit-21k
283•schopra909•3d ago•29 comments

Show HN: Stroq – a local audit of what your coding agent did and why

https://github.com/AGGIB/Stroq
92•agybay_07•2d ago•34 comments

Show HN: Agents infer Lego mechanisms from sources, then animate them

https://github.com/anteloc/ldraw-mecha/tree/v0.5.0
31•antelocnova•1d ago•2 comments

Show HN: Live songbook for guitarists

https://kantamigo.com
3•gosen•14h ago•0 comments

Show HN: Laplace's Scissors – A tool for directly editing LLM weights

https://github.com/Miyamoto-Renya/LaplacesScissors
2•032renya•14h ago•0 comments

Show HN: We made a new theme to increase engagement on our website

https://zenmemes.com/threads/thread-20261107173646-27caa60f/
5•forgotmypw17•14h ago•4 comments

Show HN: Tumblr Likes Calendar: Browse Your Likes by Date

https://www.hakuren-dev.blog/
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Show HN: Firenook – Firebase emulators in Rust: 40× faster writes, 10× less RAM

https://firenook.dev/
171•sanjevirau•2d ago•30 comments

Show HN: FoilGateway–Linux firewall gateway with telemetry blocking (2×Ethernet)

https://github.com/iBgeek/FoilGateway-Network
2•Codemonkey2k5•15h ago•0 comments

Show HN: AegisKernel – Zero-trust POSIX runtime for AI agents in <0.016ms

https://adikshatriyag-crypto.github.io/aegis-kernel/
13•adityawebde•1d ago•3 comments

Show HN: I built a tool that prices a pre-built PC part by part

https://pcdealcheck.com/
119•adlep•3d ago•85 comments

Show HN: Agentic Identity Broker, OAuth Delegation for AI Agents

https://github.com/zalando-incubator/agentic-identity-broker
23•jbspeakr•1d ago•3 comments

Show HN: After a decade of reversing, I got co-op working in DOS Wing Commander

https://fireflyk64.github.io/wcmulti/
255•daniel_rh•3d ago•40 comments

Show HN: Uncracked City, detective game where you question LLM suspects that lie

https://uncracked.city
127•passkey1510•4d ago•69 comments

Show HN: An online shop where your friends can hurry the courier

https://www.dopaminechic.com/
6•AmsterErdo•20h ago•3 comments

Show HN: Overhead – the planes overhead, painted on an e-ink frame

https://github.com/dmellok/tesserae-widget-overhead
12•xDaftTurtle•1d ago•0 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.