Native EPUB & DOCX & PDF generation Need feedback on a new offline writing app

mkltkn · 05-12-2026, 04:51 AM

Hi everyone,

A couple of weeks ago, I introduced myself as a developer obsessed with typography and e-book formatting. Today, I wanted to share what I’ve been building and ask for this community's brutally honest technical feedback.

Like many of you, I was frustrated by writing software that either requires a monthly subscription, locks you into a Mac ecosystem (like Vellum), or forces you to install heavy dependencies like Pandoc just to get a clean DOCX or EPUB export.

So, I built Mergen Ink. It's an offline-first, native writing app for Windows, Mac, and Linux.

I used Tauri 2 (Rust + SvelteKit) to keep it extremely lightweight. But the part I'm most proud of—and the reason I'm posting here—is the export engine.

I completely ditched Pandoc. Instead, I wrote a custom AST-to-EPUB/DOCX parser entirely in Rust. It generates EPUBs and DOCX files entirely locally, in milliseconds, without requiring the user to install anything else.

Under the hood:

100% Offline & Local: Everything is saved to a local SQLite database on your machine.

Zero External Dependencies: The Rust engine handles all the rich-text conversions natively.

Just released v0.1.10: Added full i18n support and a brand new distraction-free UI.

Free & No Subscriptions: It's a pay-once, own-forever model (currently completely free).

Since this community knows EPUB structures, metadata handling, and e-reader CSS quirks better than anyone else on the internet, I would be honored if some of you could export a test EPUB from the app, unzip it, and "roast" the output.

Are the HTML/CSS structures clean enough?

Is there any specific metadata handling I should improve for older e-readers?

You can grab the app here: https://mergen.ink

I’m the sole developer, so any technical feedback on the generated EPUB structures would be immensely helpful. I am ready to take notes!

Cheers,

JSWolf · 05-12-2026, 03:57 PM

If you really want to make an improvement that would get more people to try your program, then remove the AI.

AI-Native Book Writing Environment <-- make this gone

A lot of people do not want AI.

BeckyEbook · Yesterday, 09:24 AM

Out of curiosity, I installed Mergen Ink, and I really like it. Even without using the AI features ("Writing" mode), it can be a useful tool for writers who just want to write, preview their work immediately, and export it.
Another plus is the UI design, which I really like.
I’ll definitely be keeping an eye on this app’s development.

05-12-2026, 04:51 AM	#1
mkltkn Junior Member Posts: 2 Karma: 10 Join Date: Apr 2026 Device: Kidle Paper White	Native EPUB & DOCX & PDF generation Need feedback on a new offline writing app Hi everyone, A couple of weeks ago, I introduced myself as a developer obsessed with typography and e-book formatting. Today, I wanted to share what I’ve been building and ask for this community's brutally honest technical feedback. Like many of you, I was frustrated by writing software that either requires a monthly subscription, locks you into a Mac ecosystem (like Vellum), or forces you to install heavy dependencies like Pandoc just to get a clean DOCX or EPUB export. So, I built Mergen Ink. It's an offline-first, native writing app for Windows, Mac, and Linux. I used Tauri 2 (Rust + SvelteKit) to keep it extremely lightweight. But the part I'm most proud of—and the reason I'm posting here—is the export engine. I completely ditched Pandoc. Instead, I wrote a custom AST-to-EPUB/DOCX parser entirely in Rust. It generates EPUBs and DOCX files entirely locally, in milliseconds, without requiring the user to install anything else. Under the hood: 100% Offline & Local: Everything is saved to a local SQLite database on your machine. Zero External Dependencies: The Rust engine handles all the rich-text conversions natively. Just released v0.1.10: Added full i18n support and a brand new distraction-free UI. Free & No Subscriptions: It's a pay-once, own-forever model (currently completely free). Since this community knows EPUB structures, metadata handling, and e-reader CSS quirks better than anyone else on the internet, I would be honored if some of you could export a test EPUB from the app, unzip it, and "roast" the output. Are the HTML/CSS structures clean enough? Is there any specific metadata handling I should improve for older e-readers? You can grab the app here: https://mergen.ink I’m the sole developer, so any technical feedback on the generated EPUB structures would be immensely helpful. I am ready to take notes! Cheers,

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05-12-2026, 03:57 PM	#2
JSWolf Resident Curmudgeon Posts: 83,494 Karma: 153646249 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	If you really want to make an improvement that would get more people to try your program, then remove the AI. AI-Native Book Writing Environment <-- make this gone A lot of people do not want AI.

Yesterday, 09:24 AM	#3
BeckyEbook Guru Posts: 981 Karma: 3600000 Join Date: Jan 2017 Location: Poland Device: Various	Out of curiosity, I installed Mergen Ink, and I really like it. Even without using the AI features ("Writing" mode), it can be a useful tool for writers who just want to write, preview their work immediately, and export it. Another plus is the UI design, which I really like. I’ll definitely be keeping an eye on this app’s development.

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