Show HN: I built an interactive HN Simulator
Hey HN! Just for fun, I built an interactive Hacker News Simulator.
You can submit text posts and links, just like the real HN. But on HN Simulator, all of the comments are generated by LLMs + generate instantly.
The best way to use it (IMHO) is to submit a text post or a curl-able URL here: https://news.ysimulator.run/submit. You don't need an account to post.
When you do that, various prompts will be built from a library of commenter archetypes, moods, and shapes. The AI commenters will actually respond to your text post and/or submitted link.
I really wanted it to feel real, and I think the project mostly delivers on that. When I was developing it, I kept getting confused between which tab was the "real" HN and which was the simulator, and accidentally submitted some junk to HN. (Sorry dang and team – I did clean up after myself).
The app itself is built with Node + Express + Postgres, and all of the inference runs on Replicate.
Speaking of Replicate, they generously loaded me up with some free credits for the inference – so shoutout to the team there.
The most technically interesting part of the app is how the comments work. You can read more about it here, as well as explore all of the available archetypes, moods, and shapes that get combined into prompts: https://news.ysimulator.run/comments.html
I hope you all have as much fun playing with it as I did making it!
Comments URL: https://news.ycombinator.com/item?id=46036908
Points: 237
# Comments: 121
Mon, 24 Nov 2025, 5:52 pm
Show HN: Cynthia – Reliably play MIDI music files – MIT / Portable / Windows
Easy to use, portable app to play midi music files on all flavours of Microsoft Windows.
Brief Background - Used midi playback way back in the days of Windows 95 for some fun and entertaining apps, but as Windows progressed, it seemed their midi support (for Win32 anyway) regressed in both startup speed and reliability. Midi playback used to be near instant on Windows 95, but on later versions of Windows this was delayed to about 5-7 seconds. And reliability became somewhat patchy. This made working with midi a real headache.
Cynthia was built to test and enjoy midi music once again. It's taken over a year of solid coding, recoding, testing, re-testing, and a lot more testing, and some hair pulling along the way, but finally Cynthia works pretty solidly on Windows now.
Some of Cynthia's Key Features:
* 25 built-in sample midis on a virtual disk - play right out-of-the box
* Play Modes: Once, Repeat One, Repeat All, All Once, Random
* Play ".mid", ".midi" and ".rmi" midi files in 0 and 1 formats
* Realtime track data indicators, channel output volume indicators with peak hold, 128 note usage indicators
* Volume Bars to display realtime average volume and bass volume levels
* Use an Xbox Controller to control Cynthia's main functions
* Large list capacity for handling thousands of midi files
* Switch between up to 10 midi playback devices in realtime
* Playback through a single midi device, or multiple simultaneous midi devices with lag and channel output support
* Custom built midi playback engine for high playback stability
* Custom built codebase for low-level work to GUI level
* Also runs on Linux/Mac (including apple silicon) via Wine
* Smart Source Code - compiles in Borland Delphi 3 and Lazarus 2
* MIT License
YouTube Video of Cynthia playing a midi:
https://youtu.be/IDEOQUboTvQ
GitHub Repo:
https://github.com/blaiz2023/Cynthia
Comments URL: https://news.ycombinator.com/item?id=46034145
Points: 82
# Comments: 28
Mon, 24 Nov 2025, 1:58 pm
Ask HN: Hearing aid wearers, what's hot?
One of my Phonak Audeo 90’s (RIC) died the other day after 5 years and I’m shopping for new. What’s your go to hearing aid currently if you’ve upgraded recently or have been thinking of doing so?
Moderate loss, have worn them for many years, enjoy listening to music and nature, but also need help in meetings and noisy environments.
Not worried about cost and wanting to get one more good deal out of work insurance before I retire.
Comments URL: https://news.ycombinator.com/item?id=46029699
Points: 79
# Comments: 20
Mon, 24 Nov 2025, 2:25 am