> For the complete documentation index, see [llms.txt](https://lfdocs.lookingglassfactory.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://lfdocs.lookingglassfactory.com/legacy/legacy-software/core-sdk/index-1.md).

# C API Overview

## Shared Libraries

One portion of the HoloPlay Core SDK is a set of shared libraries (DLL, dylib, so) for Windows 32, Windows 64, Mac, and Linux. The primary functionality provided by these libraries is to communicate with [**HoloPlay Service**](/software/looking-glass-bridge.md), allowing developers to show a 3D image, to load calibration data, and to determine window position for the Looking Glass.

## Header Files

This is a set of files that provide easy-to-use functions to make API requests. They also expose the structure of making such requests to allow users to make custom requests when necessary — so long as HoloPlay Service is capable of handling these requests. `HoloPlayShaders.h` exposes the shader information so the developer can take this code and create a shader in the program they're using.

[**`HoloPlayCore.h`**](/legacy/legacy-software/core-sdk/index-1/index.md) — a set of helper functions that simplify the most commonly needed functionality and make functions from `libHoloPlayCore.h` more readable.

[**`libHoloPlayCore.h`**](/legacy/legacy-software/core-sdk/index-1/libholoplaycore.md) — a set of functions for communicating with HoloPlay Service.

[**`HoloPlayShaders.h`**](/legacy/legacy-software/core-sdk/index-1/holoplayshaders.md) — a simple header file containing the GLSL lenticular shader to convert a quilt into a 3D image as a string.