Koodo is an all-in-one Open Source e-book reader for Linux

There are several e-book readers available for Linux desktop users.
Almost all distros come with a document reader that can open PDF files. It may also support other file formats like epub or Mobi, but that’s not guaranteed.
That’s why specialized apps like Foliate and Caliber are needed to read and manage e-books in different formats.
Recently, I came across another open source software that offers several great features for an e-book reader.
Koodo: It has everything you can think of
Koodo is an all-in-one open source ebook reader with features to help you better manage and read your ebooks. It is a cross-platform app that you can download on Linux, Windows, and macOS. You can even use it in a web browser.
The UI looks modern, probably because it’s an Electron app. You will need to import the books and add them to Koodo. It does not import books by folders. However, you can select multiple files to import. Do you have too many books? Add some to your favorites for quick access.
I used the AppImage format, and for unknown reasons it didn’t show the thumbnails of the file.

It supports popular ebook file formats like PDF, Mobi, and Epub. But it does not stop there. It also supports comic book formats like CBR, CBZ, and CBT. There is more. It can also read FictionBooks (.fb2), Markdown and Rich Text Format (RTF), as well as MS Office Word documents (Docx).
Along with supporting the large number of file formats, it also provides several features to enhance your reading experience.
You can highlight texts and annotate them with text notes. You can also search for the selected text in the current document or on Google.

Highlighted text and notes are accessible from the sidebar of the main application window.
There are options for text-to-speech and translation of selected text. However, neither feature worked in my testing. I used the AppImage version of Koodo.
Koodo supports various layouts. You can read documents in one-column, two-column, or continuous scrolling layouts. For ePub and Mobi formats, it automatically opens in a two-column layout. For PDF, single column layout is selected by default.
You can customize the user interface according to your taste. Change fonts, size, paragraph spacing, text color, background color, line spacing, brightness, and more.

Koodo supports night reading mode as well as five different themes. You can switch between themes according to your preferences.
You can also sync your books and reading data (like highlights, notes, etc.) across devices with Dropbox or other cloud services that support Webdav protocol.

Get Koodo on Linux
If you want to experience Koodo for experimentation, you can try its online version. You can use Koodo in a web browser. Your data is stored locally in the browser, and if you clear the browser cache, you lose the data (highlights, notes, etc., but not the books stored on your computer).
If you like its features, you can choose to install Koodo on your computer.
Several options are available for Linux users. You have a deb file for Debian and Ubuntu based distros, RPM for Red Hat and Fedora and Snap, AppImage and an ex file for all distros.
You can get the installer of your choice from the project homepage.
Conclusion
Koodo is not perfect. It has a huge list of features, but not everything works perfectly, as I found during my tests.
Still, it is a good app that has the potential to become popular among users. There are only a few apps that pack so many features.
Kudos to developer Koodo for creating a promising open source app for desktop users.
You can visit the project repository to review the source code, report bugs, or show the developers some love by featuring the project.