CopperSpice is a set of individual libraries which can be used to develop cross platform software applications in C++. It is a totally open source project released under the LGPL V2.1 license and was initially derived from the Qt framework. Over the last several years CopperSpice has completely diverged, with a goal of providing a first class GUI library to unite the C++ community.

Our motivation for developing CopperSpice was to change the fundamental design and turn the existing framework into a set of libraries for C++ developers. We are accomplishing this by leveraging modern C++ functionality, new technology, and modern tooling. CopperSpice currently requires C++17 or newer.

You can use CopperSpice with any existing tool chain such as GCC, clang, or MSVC. A C++ program using the CopperSpice libraries can be developed using any editor such as VI, emacs, or Diamond and built using CMake from a shell command line. For an integrated environment Visual Studio or QtCreator can be used for development, building, testing, and deployment.


CopperSpice consists of the following libraries which can be linked into any existing C++ application.

Date/Time, Containers (QVector, QList, QMap, QHash, QStack, etc), File System, JSON, Strings (utf8, utf16)
File Dialogs, Menus, Widgets (QCheckbox, QPushbutton, QLineEdit, etc), Printing
Audio, Video
TCP, HTTP, FTP, IPv6, DNS lookups, SSL, URL support
Rendering Context, Shader
JavaScript engine which can be embeded in your application
SQLite, PostGRES, MySQL, etc
Renderer, Widget
Web View, Web Page
DOM, Reader
Schema, Xml Query

  • Meta-Object Compiler (moc)
    • The Meta-Object Compiler is no longer required for generating reflection meta data in CopperSpice
    • Since moc is no longer required it was completely removed
    • All functionality originally provided by moc was replaced with compile time templates
    • CopperSpice automatically generates meta data for processing Signals/Slots and Introspection
    • A template class can now inherit from QObject with no restrictions on data types
    • Complex data types can be used as a signal or slot argument, for example this is valid in CopperSpice: QMap<QString, int>
    • Removal of moc simplifies the build process

  • Benefits of CopperSpice
    • Extensive use of modern C++ functionality
      • templates, variadic templates, lambdas
      • expression SFINAE
      • threading model
      • move semantics, override
      • constexpr, decltype, type traits, tuple
      • strongly typed enums
    • Redesigned all container classes
      • Composition is used to wrap the C++ standard library containers
        • QVector, QList, QStringList, QLinkedList, QSet, QStack, QQueue
        • QMap, QHash, QMultiMap, QMultiHash
      • Supports both the STL and Qt API
      • Implement QMultiHash and QMultiMap as separate classes from QHash and QMap
      • Reverse iterators added
      • Removed copy on write semantics
      • Added QFlatMap
        • Ordered map which stores elements in contiguous memory as a sorted vector of pairs
        • Similar API to QMap

    • CopperSpice includes a majority of the Qt 5 classes
    • Improved CsNetwork and support for OpenSSL 1.0.x
    • Support for TLS and SPDY added
    • Add support for SHA-2 and SHA-3
    • Reimplemented atomic support (QAtomicInt, QAtomicPointer) wrapping the C++ standard library functionality
    • Enhanced CopperSpice to use STL algorithms rather than hand rolled algorithms
    • Removed support of obsolete platforms
    • QLocale classes refactored to use UTF-8 string classes
    • Update codec classes to use UTF-8 string classes
    • High DPI support
    • Moved to Unicode 11, added support for Harfbuzz 2 for text shaping
    • Improved platform specific support
    • Redesigned plugin system

    • Integration of CsSignal
      • Improved thread aware Signal/Slot delivery
      • Increased efficiency while maintaining the full Signal/Slot API
      • Deadlocks in Signal/Slot processing have been eliminated
    • Integration of CsString
      • Improved storage to properly represent Unicode strings
      • Added new QString8 (UTF-8) and QString16 (UTF-16) classes
      • QString is synonymous with QString8
      • Moved various formatting methods to the new QStringParser class
      • Developed a new QRegularExpression class which uses iterators internally to handle UTF-8 and UTF-16
      • Created a new QStringView class which works correctly with the new QString classes
      • Remove string surrogate checking since it is not required with UTF-8 / UTF-16 encoding

    • Building
      • CopperSpice libraries are built using modern CMake syntax
      • C++ applications using CopperSpice can be built with CMake or any other build system of your choice

BSD Libraries

For more information refer to our presentations from CppNow, CppCon, and our YouTube videos. Presentations

Converting to CopperSpice

The process of converting to CopperSpice is simple and quick. Simply convert your Qt application header files one time using our PepperMill utility. The Makefiles from our demo program KitchenSink, DoxyPress,or and the Diamond Editor applications can be used as a guide to create your project files.

Getting Started

The CS Overview documentation includes how to build CopperSpice from source, setting up a project using CopperSpice, and how to migrate from Qt to CopperSpice.  CS Overview Documentation

Contacting CopperSpice

  • Ask questions or request a feature on our GitHub repository  CopperSpice  DoxyPress
  • Join a discussion on our forum  Forum
  • Email the co-founders: info [at]