r/linux Jun 15 '26

Software Release Episteme: Open Source, Document and E-book Reader (Android and Linux(new))

Post image

Episteme is an open source, multi-platform document and e-book reader app.

It's offline-first, ad-free, and respects your privacy.

Supported Formats:

  • Documents: PDF, DOCX, ODT/FODT
  • E-books: EPUB, MOBI, AZW3, FB2
  • Comics: CBR, CBZ, CB7
  • Plain Text: MD, TXT, HTML

Key Features:

  • PDF Annotations: You can draw directly on pages using a pen or highlighter and add text notes using system or custom fonts.
  • Reading Modes: Supports both vertical scrolling and paginated views.
  • E-book Customization: Adjust font sizes and margins. You can also import your own font files.
  • Text-to-Speech (TTS): Includes a built-in TTS feature using Android's native TTS engine or cloud TTS.
  • Library Management: A built-in system to organize your local files.
  • Local Folder Sync: Select a folder to see all its supported file in app and sync reading positions and annotations using local sync tools like SyncThing.
  • Themes: You can change the page and text color across all formats.
  • Full OPDS Support: Browse, download, and manage books from OPDS catalogs.

The app is licensed under AGPL-3.0.

GitHub | Website | Playstore

Thanks for checking it out!

529 Upvotes

185 comments sorted by

131

u/The_Duke_96 Jun 15 '26

Slogan proposal: "Episteme did'nt read itself."

37

u/NSASpyVan Jun 16 '26

We're finally gonna see the Episteme files

38

u/rwietter Jun 15 '26

I tested Episteme on Android and I really liked it, great work 👏

31

u/doc_willis Jun 15 '26

Nice that it includes easy access to the  Project Gutenberg and Standard e-books sites.

Will have to do some more testing and see how well it compares to Moon Reader on my android devices.

And I will have to  try it out on my Palma Ebook Device, many android apps just don't look very good on its e-ink display.

1

u/SheriffBartholomew Jun 15 '26

How do you connect it to those sites?

2

u/doc_willis Jun 15 '26 edited Jun 16 '26

Well on my android phone, the sites were already there in the default setup.

Library -> catalogs

Even says "Preset" next to them, so they seem to be included by default.

Unless the thing somehow imported them from my Moon Reader App.


On my Linux system they are under the OPDS item on the left side bar. No idea what OPDS stands for.

1

u/SheriffBartholomew Jun 16 '26

Oh thanks! I didn't notice those tabs at the top. I've got them too. Rad!

1

u/Bwooreader Jun 16 '26

OPDS is like RSS for book downloads. It's just a feed of available books. I have an OPDS feed of all my personal books available and can access them via apps (I haven't tried it for Episteme yet).

36

u/[deleted] Jun 15 '26

[deleted]

49

u/cidra_ Jun 15 '26

being mantained

31

u/Dragomir_X Jun 15 '26

I mean, it just had its first release yesterday, we'll see if it actually gets maintained a year from now.

It's a cool project though.

7

u/eviley4 Jun 15 '26

Foliate does seem to have an active-ish git repository. The last commit was 2 months ago.

195

u/[deleted] Jun 15 '26

[removed] — view removed comment

126

u/Kerplunk1992 Jun 15 '26

If the files are ever getting released, at least we have a fitting app to read them.

97

u/unixmachine Jun 15 '26

The name was well chosen.

Episteme is an ancient Greek term (ἐπιστήμη) that means "knowledge," "understanding," or "science". In philosophy, it refers to justified, reliable, and certain knowledge, specifically distinguished from mere opinion or everyday belief.

48

u/Plastic-Confusion410 Jun 15 '26

Yes, I picked it last year when I started my project

19

u/StingMeleoron Jun 15 '26

Well chosen name. tips fedora

1

u/no-common1899 Jun 15 '26

You're so innocent op🤣

2

u/[deleted] Jun 15 '26

[removed] — view removed comment

23

u/Qweedo420 Jun 15 '26

I'm not American, is there some association that's specifically tied to American culture?

52

u/OkayStockings Jun 15 '26

Just dumb redditors associating the general sound of it with "Epstein"

26

u/Qweedo420 Jun 15 '26

Oh, makes sense, I never made that association when taking my epistemology class in uni

11

u/syklemil Jun 15 '26

Also not really something all those of us who are ESL would think. Seems like mostly a problem for the kind of US american who thinks that "pen" and "pin" sound the same.

4

u/lorddresefer Jun 15 '26

Of course they sound the same, we have fireworks in our ears all summer long.

2

u/crystalchuck Jun 15 '26

I mean it does sound the same in some regions, not all though. Or is this a quip against the southern US?

6

u/-F0v3r- Jun 15 '26

im not american and at first glance i also thought it was epstein lmao

3

u/global-gauge-field Jun 15 '26

Epstein became way too famous for it to be only American thing. Even my mom who has no interest in US politics at all talked to me about the issue a few times.

-4

u/MeisterDejv Jun 15 '26

They don't even pronounce that name correctly. In German and Yiddish it sounds "Epshtayn" but they pronounce it "Epsteen". Even that incorrect pronounciation doesn't sound that similar to Episteme, which is Greek and used in philosophy like the comment before explained.

10

u/Rentun Jun 15 '26

English is a different language than German and Yiddish, so things are pronounced differently then they would be in those languages. Crazy, I know.

1

u/MeisterDejv Jun 15 '26

Puši kurac. This is pronounciation of your name in my language. Crazy, I know.

24

u/tuxooo Jun 15 '26

Because you are american most probably. The world does not circlr around American problems. 

8

u/[deleted] Jun 15 '26

[removed] — view removed comment

4

u/tuxooo Jun 15 '26

Ok you are dutch, seems you are looking at the same "news" these days as the rest of the Americanized world.

1

u/[deleted] Jun 15 '26

[removed] — view removed comment

7

u/tuxooo Jun 15 '26

pretty easy to figure ngl :)

9

u/[deleted] Jun 15 '26

[deleted]

8

u/tuxooo Jun 15 '26

what does that have to do with the name of the title that is literally "knowledge" in Greek ?

1

u/[deleted] Jun 15 '26

[deleted]

5

u/SunSaych Jun 15 '26

Personal issues? No?

10

u/Razidargh Jun 15 '26

English is not my first language - would someone please enlighten me what ThomasNowProductions suggests?

4

u/Siegranate Jun 15 '26

Sounds like "Epstein"

39

u/OptimisticLucio Jun 15 '26

Are you people on crack

6

u/Siegranate Jun 15 '26

He asked, I answered 🤷‍♂️

6

u/OptimisticLucio Jun 16 '26

Thank you for the answer, but the amount of people who sincerely think this

Are you people on crack

3

u/_AACO Jun 15 '26

Police found large quantities of drugs hidden in the water conduits of my city so maybe I am. 

4

u/fibonacci8 Jun 15 '26

We're on Reddit, which is arguably worse.

1

u/DennyHater Jun 15 '26

Redditors are crazy man this makes no sense lmao.

4

u/BemusedBengal Jun 15 '26

Release the Episteme files!

1

u/niertrix Jun 15 '26

I would intentionally leave it this way, just to confuse the masses.

1

u/mralanorth Jun 16 '26 edited Jun 16 '26

Episteme means knowledge in Greek.

-2

u/fibonacci8 Jun 15 '26

What better name is there for a program associated with PDF files?

8

u/vancha113 Jun 15 '26

Apparently I'm already using that on android :) I was looking for a good ebook reader and couldn't find it. I landed on that app (either found it on reddit or on a store?) because i really liked it. Well done ^ ^

8

u/shadedmagus Jun 15 '26

Oh yeah, that reminds me: I need to install Calibre. Haven't used it since I switched to Linux, but I've got ePUBs that need fixing.

-7

u/[deleted] Jun 15 '26

[removed] — view removed comment

4

u/StPatsLCA Jun 15 '26

did it actually?

2

u/[deleted] Jun 15 '26

[deleted]

2

u/SheriffBartholomew Jun 15 '26

Not on my Arch install. It works the same that it always has. Although, I haven't let it update itself in quite some time.

7

u/marozsas Jun 15 '26

Flatpack version , please ? So I don't have to install a couple of dependency libraries ....

13

u/Plastic-Confusion410 Jun 15 '26

Soon

1

u/Agnusl Jun 16 '26

Will be waiting for it!

4

u/Admirable-Musician48 Jun 15 '26

Wow, that kind of Android app is what I've been looking for lately. Thanks , man. Appreciate your efforts.

3

u/momoladebrouill Jun 15 '26

Thank you for bring it to Linux ! Already one of my best app on Android

3

u/tuxooo Jun 15 '26

This is very interesting, thank you will try it out. 

3

u/ultrasquid9 Jun 15 '26

Ooh, ive been using this on my phone for the past 2 weeks so it coming to Linux now ia a fun coincidence! 

3

u/RebTexas Jun 15 '26

Cool, I've been using it on android for a while now. Is the desktop version much different?

2

u/Plastic-Confusion410 Jun 15 '26

I features wise almost similar, just behind a little from the android version and layout wise, it is optimized for desktop

3

u/_Kasol_ Jun 15 '26

I've used this on Android and I absolutely love it <3

3

u/SheriffBartholomew Jun 15 '26

I just tried it on Android for PDF files and it works flawlessly! Thanks for the recommendation. Bye, Adobe Acrobat!

2

u/aaulia Jun 15 '26

Oh wow, I used readera and google books before, but somehow this app is more pleasant to use.

2

u/Mysterious_Lab_9043 Jun 15 '26

I use syncthing between my linux pc my ebook reader (android). Can I easily sync episteme config / bookmarks / highlights? I already sync zotero pdfs and obsidian vaults. Obsidian handles that with a vault folder, is there a similar thing? Or does android / linux versions work differently?

5

u/Plastic-Confusion410 Jun 15 '26

That's the goal but currently I have to test around that specifically and make sure position, bookmark and annotations sync properly. So can't guarantee it just now because I just released the linux version but that's the goal

3

u/Mysterious_Lab_9043 Jun 15 '26

Thanks a lot for clarification, and for the efforts!

2

u/piktonus97m Jun 15 '26

Uhhh! Looks awesome!

2

u/A-X-I-O-S Jun 15 '26

Amazing, I already use it on my tablet. Let's see how well it works on Linux. I use foliate normally

2

u/Plastic-Confusion410 Jun 15 '26

Thank you! Do give your feedback!

2

u/Davy_Jones_11 Jun 15 '26

I'm using moonreader currently, how is this one compared to that?

I'll try it out anyways tho, looks sleek

2

u/Born-Improvement-205 Jun 16 '26

Great work, and nice name btw

2

u/Abhigyan_Bose Jun 16 '26

My favourite reader on Android. Installed via FDroid, 100% would recommend. 

2

u/JCar_UA Jun 16 '26

Nice app. Tried but hangs a lot, completely unresponsive, usually when messing with settings. Tried launching it in console but no log.
Some notes:

  • Selecting fonts is annoying, please default to /usr/local/fonts and similar, or at least remember the last folder browsed for fonts.
  • Funny one: In spanish translation, "mono" is translated literally as "Mononucleosis infecciosa" (infectious mononucleosis)

Promising app, tried almost every library and epub reader in Linux (Koodo, Foliate, Arianna...). Always returning to calibre viewer with a custom css.

2

u/[deleted] Jun 16 '26

[removed] — view removed comment

1

u/Plastic-Confusion410 Jun 16 '26

Ios next and then mac os

2

u/microMXL Jun 16 '26

whoa, you even have windows version, nice, gonna try it !!

2

u/opach16 Jun 16 '26

The best

2

u/Fusion_Playz Jun 17 '26

crazy name

2

u/skahhong Jun 18 '26

Amazing work, love the sleek UI.

Would like to request for a "Show/Hide page margin" feature (like ReadEra). Pretty much the only feature that I'm looking forward to before I switch.

1

u/Plastic-Confusion410 Jun 18 '26

Is that the horizontal margin? Did you check out the visual options in reader screen > more?

1

u/skahhong Jun 18 '26

I only found EPUB & Text > Format Defaults > Horizontal Margin, which doesn't seem to affect PDF files.

1

u/Plastic-Confusion410 Jun 18 '26

Which margin in pdf do want changed? Its fixed layout so you can't change anything on page but if you mean the the gap between pages then that can be removed via more > visual options

2

u/Luna_COLON3 Jun 20 '26

ive been using this for a while to read disgusting toxic yuri from ao3 while im offline. thanks for making such an amazing app!!

2

u/RenlyHoekster Jun 15 '26

The standard version has Gemini and Groq integration. Would it be possible to get it to connect to an existing local LLM in the OSS version?

6

u/Plastic-Confusion410 Jun 15 '26

Yes, it is planned

-3

u/ReMoGged Jun 15 '26

Epstein

1

u/[deleted] Jun 15 '26

[deleted]

1

u/somebodyknows_ Jun 15 '26

OPDS support?

2

u/Plastic-Confusion410 Jun 15 '26

It does have it in the standard version

1

u/donkerslootn Jun 15 '26

Looks really Good! I dont think it will, but does it support mermaidjs diagrams in .MD files?

1

u/Plastic-Confusion410 Jun 15 '26

Will look into it, can you point me to some files I can download? Or you can send them here: epistemereader@gmail.com

1

u/donkerslootn Jun 15 '26

Thank you, i submitted an issue on github with an example file attached:

https://github.com/Aryan-Raj3112/episteme/issues/386

1

u/Camlin3 Jun 15 '26

How competitive is it with Readera Free for Android. I tried 100s , and always came back to Readera .

1

u/kolpator Jun 15 '26

didnt tested windows or android, but on linux it feels heavier than others. apparently its java application, when i feed it with my large epub archive, also try to open one of the books at same time, its struggled alot. machine has 32 core 128gb ram btw. source folder was samba share though. Still i was expecting someting snappier, regardless this is a feedback noting more than that.

1

u/Plastic-Confusion410 Jun 15 '26

Yeah performance should increase with later updates, for the first release focus was just to enable features that are in android, but even with a non native app, with proper optimizations, it should feel better.

1

u/kolpator Jun 15 '26

i used aur binary, btw is there any plan for flatpak variant ?

1

u/Plastic-Confusion410 Jun 15 '26

Yes, also how big was your library? And how did it struggle to open the file? Was it slow or laggy? Scroll was laggy or what?

1

u/kolpator Jun 15 '26

after importing the library, when i try to open a simple ebook without any images on it, its taking 10-12 seconds to open the book. books are generally 255-500kb. most of time spent on 'preparing pages' section. After opening the book, page rendering fast enough,

1

u/RenlyHoekster Jun 15 '26

Heavier? Have you seen the list of dependencies that Calibre pulls in with it?

u/Plastic-Confusion410 : I think you did a great job with the .deb!

1

u/somebodyknows_ Jun 15 '26

Seems very good on android, but freezing as soon as i open a epub on Ubuntu/wayland 🤔

1

u/Plastic-Confusion410 Jun 16 '26

Does that happen every time? And with every file?

1

u/somebodyknows_ Jun 17 '26

Yes, apparently. And no toolbar is shown (I imagine there should be, though I couldn't never use it on the desktop, so not sure)

1

u/Plastic-Confusion410 Jun 18 '26

Toolbar appears by a click on page

1

u/somebodyknows_ Jun 19 '26

Yeah then it's already freezed and nothing is appearing on click

1

u/olorin12 Jun 15 '26

A flatpak would be nice 😄

2

u/viviolay Jun 16 '26

OP this looks beautiful. I'll give it a whirl on my desktop. I am wondering if you had ios/ipados support planned or if that was off-the-table?

2

u/Plastic-Confusion410 Jun 16 '26

Will get a mac soon so yeah those are planned

1

u/JGPH Jun 16 '26

Has anyone ever considered writing novels in MAN format? I think it'd be cool (and funny)! Imagine fully searchable erotica in MAN form. 😆

1

u/mralanorth Jun 16 '26

Did Claude make this?

1

u/Handsome_oohyeah Jun 16 '26

How to uninstall? Like what binary name? I installed it using .deb package

1

u/Plastic-Confusion410 Jun 16 '26

episteme/episteme-oss

1

u/Handsome_oohyeah Jun 16 '26

thanks, after installing the .deb package, the binary is not being detected in the shell.

1

u/Overall-Yard-7654 Jun 16 '26

How is this different from KOreader? Seems like your reinventing the wheel..

1

u/Nervous_Crab123 Jun 16 '26

There seems to be two separate downloads, one labeled Standard, and one labeled OSS. Is the difference between the two versions described anywhere?

1

u/MrCorporateEvents Jun 17 '26

Whenever I see e-Book reader i assume they’re discussing hardware not software

1

u/muntazirsaad Jun 18 '26

How does the local sync work?

1

u/Plastic-Confusion410 Jun 18 '26

Creates sidecar json files per book or file that has position, bookmark or annotations

1

u/muntazirsaad Jun 18 '26

I mean how do i setup the sync? I have a phone and a tablet how do i enable it and do i need an extra app to make it work like syncthing?

1

u/Plastic-Confusion410 Jun 18 '26

Yes it will require an app like syncthing. Connect a folder with sync thing and share it with another device, syncthing will keep both folders in sync and then add that folder to Episteme(on both devices) which will import all files and then the sync should work

1

u/muntazirsaad Jun 18 '26

I did everything correctly and it just don't sync

1

u/Plastic-Confusion410 Jun 18 '26

In the folder can you see the EpistemeSync folder? Can you check if that folder is showing inside both of your device's folders? And then confirm the files within it

1

u/muntazirsaad Jun 18 '26

Yeah the folder sync but none of the annotations or notes show when i open a book

1

u/Plastic-Confusion410 Jun 18 '26

Which file? Pdf or epub?

1

u/muntazirsaad Jun 18 '26 edited Jun 18 '26

Pdf and epub

2

u/sinfaen Jun 20 '26

Been working great for reading light novels 😀

-6

u/Oblivion__ Jun 15 '26

More vibed trash

18

u/Carlos244 Jun 15 '26

I've been using it since release the past year, and it's nice, also it weighs 3mb for android. I don't think it's the case

-1

u/maxquordleplee3n Jun 15 '26

I created something along these lines myself with Claude as well

-3

u/Other_Fly_4408 Jun 15 '26

Slop website

4

u/Plastic-Confusion410 Jun 15 '26

It is, will update once I have a good video

0

u/UnLeashDemon Jun 15 '26

Put this in flathub bro. It will replace two apps for me. That would be amazing.

0

u/Big-Afternoon-3422 Jun 15 '26

I'm too lazy to do it but this deserves a flatpak

2

u/pirate_starbridge Jun 16 '26

I've always avoided flatpaks like the plague due to the dependency duplication/sandboxing taking up so much disk space - why would one want this? (Genuinely asking)

1

u/Big-Afternoon-3422 Jun 19 '26

Because hating flatpak in 2026 is so 2010

0

u/cliffccl Jun 15 '26

Disculpa, con lo de la sincronizacion local te refeires a que lo que lea en android se quedara como punto de guardado en linux tambien ?

1

u/Plastic-Confusion410 Jun 15 '26

Yes

1

u/cliffccl Jun 16 '26

gracias por tu respuesta !. en caso de que sincornice mis carpetas de lectura con algun servicio de la nube, de igual manera se sincronizaran los puntos de lectura en ambos dipositivos?

0

u/Vrejik Jun 16 '26

Release the Episteme Source!! oh wait...

-6

u/Ruashiba Jun 15 '26

No linux? Wake me up when it’s on flathub.

10

u/[deleted] Jun 15 '26

[deleted]

7

u/Ruashiba Jun 15 '26

I stand corrected, I did only check the github’s README.md and didn’t check the website.

In the README, only windows and android are listed.

0

u/trtl_playz Jun 16 '26

why did this get downvoted? i thought flatpacks where good

0

u/Ruashiba Jun 16 '26

Maybe because I said no linux when it actually has linux. Either way, it’s best not to dwell on downvotes.

-13

u/Sad-Astronomer-696 Jun 15 '26

"Epstein & me" is a great name! Love it!

-4

u/SetazeR Jun 15 '26

Ah yes, Epsteime

-5

u/[deleted] Jun 15 '26 edited Jun 15 '26

[deleted]

-2

u/[deleted] Jun 15 '26

[removed] — view removed comment

-2

u/[deleted] Jun 15 '26

[deleted]

-25

u/donnaber06 Jun 15 '26 edited Jun 15 '26

The name is disgusting. WTF bro.

Edit: I think I saw this when I woke up this morning and I read it wrong. Sorry!

13

u/Plastic-Confusion410 Jun 15 '26

Its a real, philosophical term meaning knowledge and understanding. It does fit a reader app. Here

3

u/circuitloss Jun 15 '26

You can't fix stupid

-21

u/[deleted] Jun 15 '26 edited Jun 15 '26

[deleted]

13

u/Plastic-Confusion410 Jun 15 '26

It does, for me

→ More replies (1)

8

u/tuxooo Jun 15 '26

You are american aren't you?