Catch2 is great for open source. It is licensed under the Boost Software License (BSL), has no further dependencies and supports two file distribution.
As a result, Catch2 is used for testing in many different Open Source projects. This page lists at least some of them, even though it will obviously never be complete (and does not have the ambition to be complete). Note that the list below is intended to be in alphabetical order, to avoid implications of relative importance of the projects.
Please only add projects here if you are their maintainer, or have the maintainer's explicit consent.
C++11 implementation of Approval Tests, for quick, convenient testing of legacy code.
A simple header-only C++ argument parser library.
Boost Asio style bindings for ZeroMQ.
Post-apocalyptic survival RPG.
A, header-only, embedded scripting language designed from the ground up to directly target C++ and take advantage of modern C++ development techniques.
The core part of the Chakra JavaScript engine that powers Microsoft Edge.
A, single-header-only, type-safe, command line parser - which also prints formatted usage strings.
The next-generation core storage and query engine for Couchbase Lite.
Header-only C++11 library to encode/decode base64, base64url, base32, base32hex and hex (a.k.a. base16) as specified in RFC 4648, plus Crockford's base32.
A High-performance Cluster Computing Engine.
Template Library of Tree Data Structures.
Open source Oracle Tuxedo-like XATMI middleware for C and C++.
A header-only library that allows CPUs to execute unmodified HIP code. It is generic and does not assume a particular CPU vendor or architecture.
A header-only template engine for modern C++.
A single-header-only library written in C++14 to glue distributed software components (UDP, TCP, shared memory) supporting natively Protobuf, LCM/ZCM, MsgPack, and JSON for dynamic message transformations in-between.
A small and easy to use C++11 library that adds a functionality set that will be available in C++14 and later, as well as some useful additions.
A small C++ library wrapper for the native C ODBC API.
A header-only framework for benchmarking small snippets of C++ code.
A polymorphic value-type for C++.
A C++ client library for Consul. Consul is a distributed tool for discovering and configuring services in your infrastructure.
A library of algorithms for values-distributed-in-time.
The C++ Database Access Library.
A small, single-header-only, library for wrapping and composing columns of text.
Wrapper Library for CUDA.
A header-only TOML parser and serializer for modern C++.
A thread-safe header-only mocking framework for C++14.
A high available cloud native micro-service application management platform implemented by modern C++.
ArangoDB is a native multi-model database with flexible data models for documents, graphs, and key-values.
Open source molecular dynamics simulation structure analysis suite of tools in modern C++.
Minimal, open-source and cross-platform audio tool for live music production.
MAME originally stood for Multiple Arcade Machine Emulator.
Newsbeuter is an open-source RSS/Atom feed reader for text terminals.
A 2D, Zombie, RPG game which is being made on our own engine.
Low level CLI app and library for execution of GCODE on Raspberry Pi without any additional microcontrolers (just RPi + Stepsticks).
SpECTRE is a code for multi-scale, multi-physics problems in astrophysics and gravitational physics.
Standardese aims to be a nextgen Doxygen.