Download SystemH | Single-Header C++ Runtime

Release Package Contents

The release bundle includes everything required to integrate SystemH into your C++ projects:

System.h
Single-header .NET Framework Base Class Library for cross-platform C++ development

1.35 MB (header)
System.Keywords.h
C# keyword shorthands (string, foreach, etc.) for opt-in C# syntax fidelity

1.0 KB (header)
System.MemoryPool.h
High-performance standalone multi-bucket slab allocator header

1.0 KB (header)
fetch_dependencies.sh
Automated cross-platform dependency setup script (compression, TLS, ODBC)

8.5 KB (bash)
system_printers.py
GDB pretty-printers script for Visual Studio Code, CLion, and terminal GDB

9.1 KB (python)
LICENSE.txt
PolyForm Small Business License 1.0.0 full legal terms and conditions

2.6 KB (text)
README.txt
Comprehensive platform dependencies guide, compiler flags, and architecture documentation

6.2 KB (text)

            SHA-256 Checksum: 3a303a484445fdfba2cf244450a8654e1a180e90d5777bc4b25d968c25447253
        

License Agreement Gate

SystemH is licensed under the PolyForm Small Business License 1.0.0:

Free for Non-Commercial Use: Personal projects, evaluation, education, and open-source software.
Free for Small Businesses: Commercial deployment is free for businesses and individuals whose total annual gross revenue is below USD $1,000,000.
Commercial Inquiries: Organizations with revenue ≥ $1,000,000 USD require an enterprise commercial license. Contact info@systemh.org.

PolyForm Small Business License 1.0.0 <https://polyformproject.org/licenses/small-business/1.0.0/> 1. Acceptance In order to receive this license, you must agree to its rules. The rules of this license are both obligations under that agreement and conditions to your grant of licenses. 2. Copyright License The licensor grants you a copyright license to make and distribute copies of the software, modify the software, and distribute your modifications, subject to the Business Threshold. 3. Business Threshold You may not run or deploy this software for commercial purposes if your Total Revenue equals or exceeds USD $1,000,000. If your Total Revenue reaches or exceeds USD $1,000,000, your license automatically terminates immediately. For commercial licensing exceeding this threshold, contact the licensor at info@systemh.org. 4. Notices You must ensure that everyone who gets a copy of any part of this software from you also gets a copy of this license and all copyright and attribution notices.

I have read and agree to the terms of the PolyForm Small Business License 1.0.0

Package: systemh-release.zip (251 KB)

Dependencies & Platform Architecture

Zero Mandatory Dependencies

Core System.h requires zero third-party dependencies beyond a standard C++17 compiler (GCC 9+, Clang 10+, MSVC 2019+). Optional advanced subsystems are opt-in via preprocessor defines:

Regular Expressions Zero Dependencies

100% native UTF-16 linear-time ReDoS-immune PikeVM engine. Built directly into core System.h.

                    No external libraries required
ESP32 / Embedded / Server Ready
                

Stream Compression -D SYSTEMH_COMPRESSION_ENABLED

High-throughput GZipStream & BrotliStream backed by zlib & Google Brotli (or ESP-IDF miniz ROM).

                    apt install zlib1g-dev libbrotli-dev
vcpkg install zlib brotli:x64-windows
                

TLS 1.3 & Cryptography SslStream / Crypto

AES, SHA-256, HMAC, and SslStream TLS 1.3 via OpenSSL on Linux, Windows CNG, or mbedTLS on ESP32.

                    Linux: -lssl -lcrypto | Win: bcrypt.lib
                

Database Connectivity System.Data.Odbc

Enterprise database access via ODBC 3.x driver manager (PostgreSQL, MySQL, SQL Server).

                    apt install unixodbc-dev | Win: odbc32.lib
                

ℹ️

Companion Web Server Note: Http.h (HTTP/3, QUIC, and WebSockets server) is an independent companion library and is not part of core System.h. QUIC dependencies (ngtcp2, nghttp3, OpenSSL 3.5+) are only required if building an HTTP/3 server.

Integration Quickstart

Drop System.h into your include path and compile with C++17 or C++20:

Linux / GCC & Clang:

g++ -std=c++17 -O2 -o my_app main.cpp -lpthread -ldl

Windows / MSVC (Developer Command Prompt):

cl /std:c++17 /EHsc /O2 main.cpp

WebAssembly / Emscripten (WASM):

em++ -std=c++17 -O3 -s WASM=1 main.cpp -o app.html

ESP32 (ESP-IDF CMakeLists.txt):

target_compile_features(${COMPONENT_LIB} PRIVATE cxx_std_17)

GDB Debugger Formatting (in ~/.gdbinit or VS Code launch.json):

source /path/to/system_printers.py