Third Party Libraries

The following table lists libraries and other third party (3p) dependencies used in constructing the Second Life Viewer.

Most of these (all the open source ones) should be available as prebuilds packaged by and for use with Autobuild.

Creating a new third party package

Need to create a new third party package? The best route may be to start with an existing package similar to the one you wish to create and modify.

Generic Layout

3p packages should vendor upstream contents using git submodules unless a source git repository for the source dependency is not available. A typical 3p package layout looks like this:

.
├── [vendor submodule]/ - Git submodule containing upstream source
├── .github/            - CI/CD and repository configuration
├── autobuild.xml       - Autobuild manifest
├── build-cmd.sh        - Script used to build the repository
├── LICENSE             - Repository licensing
└── README.md           - Repository readme

Contributor Instructions

The general workflow for contributing changes to a 3p library looks like this:

1. Fork the repository and make changes. Be sure to test your work locally.
2. Create a PR (Be sure to follow PR Etiquette and our Code of Conduct)
3. Have this PR reviewed and merged
4. Done! The maintainer should cut a new version as appropriate using the workflow described below.

Maintainer Instructions

A properly versioned and promoted release of 3p-zlib-ng

If you are a 3p package maintainer you will want to follow these instructions to review and release new versions:

1. Review PRs quickly, and merge them directly into the default branch once approved
2. Cut a new release by using Github's Releases feature:
   1. Navigate to Repository -> Releases and click "Draft new Release"
   2. Click Choose a tag and create a new tag using the vUPSTREAM-rRELEASE format described below
   3. Click Generate release notes and edit them as appropriate. Keep the title of the release equal to the version being used.
   4. Click Publish release

After the release is published, CI/CD should be triggered by the addition of the new tag, and provide a nice set of packages and instructions for consumers to use.

Version format

3p packages should be released using the following version schema:

Format

  vUPSTREAM-rRELEASE

  Example: v1.0.0-r2 (Second vendored release of v1.0.0 of this library)

  UPSTREAM - Upstream package version. ex. 1.0.0 or 6.7
  RELEASE - Vendored release number, ex. 1, 2

List of third party libraries

Library	Repository	License	Upstream Home	Description
apr_suite	3p-apr	Apache License	http://apr.apache.org/	"A set of C functions which provide a portable and consistent interface into operating system - or simply widely useful - functionality. We primarily use it for threading and socket i/o. This is actually three packages, apr, apr-util and apr-iconv."
boost	3p-boost	Boost License	http://www.boost.org/	A set of portable C++ libraries which provide a wide set of functionality. Used primarily for tokenization.
curl	3p-curl	BSD-styleB	http://curl.haxx.se/libcurl/	Handles moving data across the net in many different protocols. Used to GET/POST/PUT/DELETE web resources.
expat	3p-expat	MIT License	https://github.com/libexpat/libexpat	XML parser.
freetype	3p-freetype	Freetype License and Others	http://www.freetype.org/	Font engine.
glh_linear	3p-glh_linear			nVidia NVParse SDK: platform-independent C++ Apple OpenGL helper library
gstreamer	3p-gstreamer	Open	http://gstreamer.freedesktop.org
havok		Commercial
jpeglib	3p-jpeglib	Open	http://www.ijg.org/	JPEG decoder library.
kdu	3p-kdu-privateLL	Commercial	http://www.kakadusoftware.com	Kakadu (KDU) JPEG-2000 decoder library.
libpng	3p-libpng	Open	http://www.libpng.org/pub/png/libpng.html	PNG image library.
libxml2	3p-libxml2	MIT License
ndofdev	3p-libndofdev	BSD-styleB		Provides joystick driver support (mac and win) for the 3DConnexion SpaceNavigator.
ogg_vorbis	3p-ogvorbis	BSD-styleB	http://xiph.org/ogg/	Audio codec and playback.
openal	3p-openal-soft	GPL	http://connect.creativelabs.com/openal/default.aspx	3D Spatial audio
openjpeg	3p-openjpeg	BSD-styleB	http://www.openjpeg.org/	An open-source JPEG-2000 library; a slower alternative to Kadaku. Used in the open source release
openssl	3p-openssl	Apache License	http://www.openssl.org/	Provides encryption for sensitive actions such as user login
sdl	3p-sdl2	zlib License	http://www.libsdl.org/index.php	The Simple DirectMedia Layer libraries are used for handling input and basic window/GL setup on the Linux client.
slvoice		Commercial		This is the Vivox provided executable (renamed SLVoice)
tut	3p-tut	BSD-styleB	http://tut-framework.sourceforge.net/	Unit test framework based on the use of c++ meta template programming. Used to test LL libraries.
xmlrpc_epi	3p-xmlrpc-epi	Epinions, Inc License	http://xmlrpc-epi.sourceforge.net/	XML-RPC protocol utility
zlib-ng	3p-zlib-ng	zlib License	http://www.zlib.net/	zlib is a lossless data-compression library which is used for a variety of network i/o and file compression.

Redistribution

Some files in the SL installation can't be freely redistributed. This means it's not possible to simply package and offer for download a modified viewer: some files must not be redistributed.

This page documents the licenses and redistribution requirements of various files used by the viewer.

Windows

These are the files that need to be shipped with the Windows version

Runtime

Microsoft components. It's not yet known whether they're redistributable.

• dbghelp.dll: Redistributable
• msvcp71.dll: C++ Runtime Library, redistributable -viewer now using msvcp80.dll when compiled with VC2005
• msvcr71.dll: C Runtime Library, Redistributable -viewer now using msvcr80.dll when compiled with VC2005

FONTS

Meta font software files

From the Readme.txt

The Meta font software files contained in this folder are the
copyrighted property of FSI FontShop International ("FSI") and are
licensed by FSI solely for use by Linden Research, Inc. and by
residents or users of Second Life in the Second Life environment,
subject to the Second Life Terms of Service.  These Meta font software
files may not be copied by residents or developers of Second Life or
used by them for any other purpose whatsoever.

• MtBkLfRg.ttf
• MtBdLfRg.ttf

NOTE: These files must be replaced for an true opensource build

Mozilla

The Gecko engine is MPL/GPL/LGPL licensed, which makes it redistributable.

• app_settings/mozilla
• freebl3.dll
• gksvggdiplus.dll
• js3250.dll
• nspr4.dll
• nss3.dll
• nssckbi.dll
• plc4.dll,
• plds4.dll
• smime3.dll
• softokn3.dll
• ssl3.dll
• xpcom.dll
• xul.dll

Kakadu

JPEG2000 library. Not redistributable. OpenJPEG is an alternative library that is redistributable

• llkdu.dll

Starting with Viewer 2.5, llkdu.dll has been phased out. The libkdu.a and kdu.lib are still not redistributable but can be built from the toolkit provided by Kakadu under a license. How to build a viewer with such a library is documented in KDU Implementation.

OpenSSL

SSL library. Redistributable.

• libeay32.dll
• ssleay32.dll

Vivox

Vivox is the component that provides the voice functionality.

• SLVoice.exe: Voice daemon. Not redistributable
• SLVoiceAgent: Exact purpose unknown. Not redistributable
• alut.dll: OpenAL, by Creative Labs. Redistributable.
• ortp.dll: oRTP project, LGPL. Redistributable.
• srtp.dll: Secure RTP?
• vivoxsdk.dll: Vivox Communications API. Not redistributable
• wrap_oal.dll: OpenAL32 by Creative Labs. Redistributable.

Unknown Libraries

The purpose and licensing of these files is not known:

• tntk.dll: Probably Vivox related -see Voice/Technical for other info on ViVox files