Ingles

The Source engine and Valve games use Third Party code for certain functions. The required legal notices for using such code are reproduced below in accordance with Valve’s obligations to provide such notices:

For Xzip/Xunzip:

// This is version 2002-Feb-16 of the Info-ZIP copyright and license. The
// definitive version of this document should be available at
//ftp://ftp.info-zip.org/pub/infozip/license.html indefinitely.
//
// Copyright (c) 1990-2002 Info-ZIP. All rights reserved.
//
// For the purposes of this copyright and license, "Info-ZIP" is defined as
// the following set of individuals:
//
// Mark Adler, John Bush, Karl Davis, Harald Denker, Jean-Michel Dubois,
// Jean-loup Gailly, Hunter Goatley, Ian Gorman, Chris Herborth, Dirk Haase,
// Greg Hartwig,Robert Heath, Jonathan Hudson, Paul Kienitz,
// David Kirschbaum, Johnny Lee, Onno van der Linden, Igor Mandrichenko,
// Steve P. Miller, Sergio Monesi, Keith Owens, George Petrov, Greg Roelofs,
// Kai Uwe Rommel, Steve Salisbury, Dave Smith, Christian Spieler,
// Antoine Verheijen, Paul von Behren, Rich Wales, Mike White
//
// This software is provided "as is", without warranty ofany kind, express
// or implied. In no event shall Info-ZIP or its contributors be held liable
// for any direct, indirect, incidental, special or consequential damages
// arising out of the use of or inability to use this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
//freely, subject to the following restrictions:
//
// 1. Redistributions of source code must retain the above copyright notice,
// definition, disclaimer, and this list of conditions.
//
// 2. Redistributions in binary form (compiled executables) must reproduce
// the above copyright notice, definition, disclaimer, and this list of
// conditions in documentation and/orother materials provided with the
// distribution. The sole exception to this condition is redistribution
// of a standard UnZipSFX binary as part of a self-extracting archive;
// that is permitted without inclusion of this license, as long as the
// normal UnZipSFX banner has not been removed from the binary or disabled.
//
// 3. Altered versions--including, but notlimited to, ports to new
// operating systems, existing ports with new graphical interfaces, and
// dynamic, shared, or static library versions--must be plainly marked
// as such and must not be misrepresented as being the original source.
// Such altered versions also must not be misrepresented as being
// Info-ZIP releases--including, but not limited to,labeling of the
// altered versions with the names "Info-ZIP" (or any variation thereof,
// including, but not limited to, different capitalizations),
// "Pocket UnZip", "WiZ" or "MacZip" without the explicit permission of
// Info-ZIP. Such altered versions are further prohibited from
// misrepresentative use of the Zip-Bugs or Info-ZIP e-mail addresses or
// ofthe Info-ZIP URL(s).
//
// 4. Info-ZIP retains the right to use the names "Info-ZIP", "Zip", "UnZip",
// "UnZipSFX", "WiZ", "Pocket UnZip", "Pocket Zip", and "MacZip" for its
// own source and binary releases.
//
///////////////////////////////////////////////////////////////////////////////

For JPEG image support:

The Source engine and SDK also make use of libraryfunctions for working with .jpg files.  Specifically, the Source engine jpeg library is based in part on the work of
the Independent JPEG Group (IJG).  The original source code and project files for the IJG's JPEG libraries may be found at:  http://www.ijg.org/files/jpegsrc.v6b.tar.gz

The following is the README. File from that archive and is produced in accordance with the legal notices...