The Open Book Touch is an eBook reader with a small, front-lit E ink display, a microSD card slot for storage, and support for EPUB and TXT files. But what really makes it different from most eReaders is that it’s a fully open source device with unusual (for eReader) features like a user-replaceable battery.Not only does it run open source firmware that can be inspected and modified, but developer Joey Castillo plans to release the hardware designs once the eReader begins shipping, allowing anyone to 3D print their own case or make other changes. Castillo has been working on this device for more than six years, and now that the design has been finalized he’s launched a Crowd Supply crowdfunding campaign with rewards starting at $149. The goal is to ship units to backers in early 2027.The idea behind the Open Book Touch is to offer an alternative to proprietary eReaders from companies like Amazon and Kobo that gives users more control over their devices. There are some pros and cons to this approach.For one thing, the 3D-printed case is a snap-fit case. You can easily take it apart and replace a broken case or remove and replace the 800 mAh LiPo battery. For another, you can load eBooks either by placing them on an SD card or over a local WiFi network: just open http://libros.local on a device connected to the same network as your Open Book Touch to send eBooks to your device. There’s no account or cloud service required.On the other hand, the Open Book Touch might not have all the things you’d expect from other eReaders. With a 4.26 inch, 480 x 800 pixel screen featuring 220 pixels per inch, the display’s not as large and text won’t be quite as sharp as you’d expect from a typical Kindle device, for example. While battery life of up to a week isn’t bad, most other eReaders have battery life measured in weeks (plural) or even months.And there’s no support for DRM. That’s probably a good thing for readers who don’t want to read eBooks with Adobe or Amazon digital rights management, but it does mean that you’ll have to wade through the legal gray area of stripping DRM from eBooks purchased from many sources and it complicates the process of reading eBooks borrowed from public libraries.That said, a big part of the reason it’s taken Castillo 6 years to bring the Open Book Touch to crowdfunding is because he wanted to make sure the hardware and software were ready. And the eReader really does seem to check a lot of boxes.Its touchscreen display has a front light with five warm and five cool LEDs, allowing you to adjust the screen brightness and color temperature. It measures 78 x 120 x 10m (3.1″ x 4.7″ x 0.4″) and weighs just 85 grams (3 ounces), making it as easy to slide into your pocket as an Xteink X4, but without the need to install third-party firmware to make it useful. And its Libros firmware is based on the new open source Focus application framework, has a “real typesetting engine” that provides line spacing options, proper hyphenation, and font settings.Out of the box, there’s support for the open source Lucida Bright (serif) or Lucida Sans (sans-serif) fonts with three font sies and support for bold and italics. Unifont is also included “as a universal fallback,” with 70,000 glyphs that will allow you to read pretty much any written language. And the user interface supports English, Spanish, French, German, Japanese, Arabic, and Hebrew “with more languages to come.”Castillo says the firmware fits on the device’s 16MB of flash storage with enough spare room for “custom fonts and additional apps,” opening the possibility of running third-party eReader software or other apps or games.Other features include an ESP32-S3 dual-core processor with built-in support for WiFi and Bluetooth LE, 8MB of SPI PSRAM, and a USB Type-C port for charging and data transfer.While the basic Open Book Touch is going for $149 during crowdfunding, Castillo is also offering an “Author’s Edition” option for $249, that will come with a “special enclosure” featuring “premium materials and finish,” although exactly what those materials will be hasn’t been disclosed yet.