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Open Source Libraries
Growl Copyright (c) The Growl Project, 2004 (BSD License)
Sparkle Copyright (c) 2006 Andy Matuschak (MIT License) EMKeychain Copyright (c) 2007 Extendmac, LLC (MIT License) SSSelectableToolbar Copyright (c) 2011 Steve Streeting (MIT License) SCEvents Copyright (c) 2009 Stuart Connolly (MIT License) MGScopeBar (Instinctive Code Source Code License) is by Matt Gemmell CocoaREST is Copyright (c) 2009, Steven Degutis (New BSD License)
YAJLDecoder is Copyright (c) 2009 Gabriel Handford (MIT License)
YAJL is Copyright 2007-2009, Lloyd Hilaiel (BSD License)
ShortcutRecorder is Copyright (c) 2006, contributors to ShortcutRecorder (BSD License) AWS SDK for iOS Copyright 2010-2013 Amazon.com, Inc. or its affiliates. All Rights Reserved. (Apache 2.0 License) ITProgressBar is Copyright (c) 2014, Ilija Tovilo (BSD License) HyperlinkTextField is Copyright (c) 2012 Toomas Vahter (MIT License) INAppStoreWindow is Copyright 2011-2014 Indragie Karunaratne (BSD License) GTMSessionFetcher is Copyright 2014 Google Inc. (Apache License) CocoaLumberjack is Copyright 2010-2015, Deusty, LLC (BSD License) LetsMove is Copyright 2009-2015, Potion Factory (Public Domain) JFBCrypt is Copyright (c) 2011 Jason Fuerstenberg. (Apache 2.0 License) PEG Markdown Highlight is Copyright 2011-2016 Ali Rantakari. (MIT and GPL2+ Licenses) RNCryptor-objc is Copyright (c) 2012 Rob Napier.(MIT License)

Open Source Binaries
Mercurial (GPL 2) Modified version with full source is included
hgsubversion (GPL 2) Modified version with full source is included
Git (GPL 2) Unmodified binaries are included with SourceTree, source code is available (version displayed in Preferences/Git)
git-flow (BSD License - forked, full source available) hg-flow (full source included) (GPL 2) Git LFS (MIT) Unmodified binaries are included with SourceTree, source code is available (version displayed in Preferences/Git)