Lagrange is a desktop GUI client for browsing Geminispace. It offers modern conveniences familiar from web browsers, such as smooth scrolling, inline image viewing, multiple tabs, visual themes, Unicode fonts, bookmarks, history, and page outlines.

Like Gemini, Lagrange has been designed with minimalism in mind. It depends on a small number of essential libraries. It is written in C and uses SDL for hardware-accelerated graphics. OpenSSL is used for secure communications.

• Beautiful typography using Unicode fonts
• Autogenerated page style and Unicode icon for each Gemini domain
• Smart suggestions when typing the URL — search bookmarks, history, identities
• Sidebar for page outline, managing bookmarks and identities, and viewing history
• Multiple tabs
• Identity management — create and use TLS client certificates
• And more! Open about:help in the app, or see help.gmi

Prebuilt binaries for Windows and macOS can be found in Releases.

This is how to build Lagrange in a Unix-like environment. The required tools are a C11 compiler (e.g., Clang or GCC), CMake and pkg-config.

1. Download and extract a source tarball from Releases. Alternatively, you may also clone the repository and its submodules: git clone --recursive --branch release https://git.skyjake.fi/skyjake/lagrange
2. Check that you have the dependencies installed: CMake, SDL 2, OpenSSL 1.1.1, libpcre, zlib, libunistring. For example, on macOS this would do the trick (using Homebrew): brew install cmake sdl2 openssl@1.1 pcre libunistring Or on Ubuntu: sudo apt install cmake libsdl2-dev libssl-dev libpcre3-dev zlib1g-dev libunistring-dev
3. Create a build directory.
4. In your empty build directory, run CMake: cmake {path_of_lagrange_sources} -DCMAKE_BUILD_TYPE=Release
5. Build it: cmake --build .
6. Now you can run lagrange, lagrange.exe, or Lagrange.app.

To install to "/dest/path":

1. cmake {path_of_lagrange_sources} -DCMAKE_INSTALL_PREFIX=/dest/path
2. cmake --build . --target install

This will also install an XDG .desktop file for launching the app.

When using OpenSSL 1.1.1 from Homebrew, you must add its pkgconfig path to your PKG_CONFIG_PATH environment variable, for example:

export PKG_CONFIG_PATH=/usr/local/Cellar/openssl@1.1/1.1.1g/lib/pkgconfig

Also, SDL's trackpad scrolling behavior on macOS is not optimal for regular GUI apps because it emulates a physical mouse wheel. This may change in a future release of SDL, but at least in 2.0.12 a small patch is required to allow momentum scrolling to come through as single-pixel mouse wheel events.

You should use a version of SDL that is compiled to take advantage of the Broadcom VideoCore OpenGL ES hardware. This provides the best performance when running Lagrange in a console.

When running under X11, software rendering is the best choice and in that case the SDL from Raspbian etc. is sufficient.

The following build options are recommended on Raspberry Pi:

• ENABLE_KERNING=NO: faster text rendering without noticeable loss of quality
• ENABLE_WINDOWPOS_FIX=YES: workaround for window position restore issues (SDL bug)
• ENABLE_X11_SWRENDER=YES: use software rendering under X11