The Linguistics Pro font family is based on the Utopia Nova font family, issued by Andreas Nolda, copyright(c) 2015, under the SIL Open Font License (OFL), version 1.1; see at http://scripts.sil.org/ofl.

The Utopia Nova font family is based on the Adobe Utopia fonts, which were
licensed by Adobe to the TeX Users Group (TUG) under the following license:

Adobe Systems Incorporated ("Adobe") hereby grants to the TeX Users Group and
its members a nonexclusive, royalty-free, perpetual license to the typeface
software for the Utopia Regular, Utopia Italic, Utopia Bold and Utopia bold
Italic typefaces, including Adobe Type 1 font programs for each style
(collectively, the "Software") as set forth below.

Adobe grants the TeX Users Group a license under its copyrights, to use,
reproduce, display and distribute the Software for any purpose and without fee
provided that the following copyright notice appears in all whole and partial
copies of the Software and provided that the following trademark symbol and
attribution appear in all unmodified copies of the Software:

  Copyright 1989, 1991 Adobe Systems Incorporated. All rights reserved.
  (alternatively, @1989, 1991 Adobe Systems Incorporated. All rights reserved.)
  Utopia(R)
  Utopia is either a registered trademark or trademark of Adobe Systems
  Incorporated in the United States and/or other countries. Used under license.

Adobe also grants to the TeX Users Group a license to modify the Software for
any purpose and redistribute such modifications, for any purpose and
royalty-free, provided that the modified Software shall not use the font name(s)
or trademark(s), in whole or in part, unless explicit written permission is
granted by Adobe. This restriction applies to all references stored in the
Software for identification purposes, such as the font menu name and other font
description fields. The TeX Users Group is also permitted to sublicense, and
grant such sublicensees the right to further sublicense, any or all the
foregoing rights through multiple tiers of distribution. The licenses granted
herein are granted in perpetuity and may not be terminated by either party
unless such termination is based on a breach of the terms and conditions herein
stated.

Adobe retains ownership of the copyright in the Software. The TeX Users Group
agrees that Adobe and its suppliers are the sole and exclusive owners of all
rights, title and interest, including all copyrights, patents, trademarks, trade
names, trade secrets and other intellectual property rights in the Software. No
title or ownership of the Software, any copies of the Software, or the patent,
copyright, trade secret, trademark, trade name or other proprietary rights
contained in the Software is transferred to the TeX Users Group.

The Adobe trademarks shall not be used in advertising pertaining to the
distribution of the Software without express prior permission from Adobe. Any
such use shall be in accordance with the Adobe trademark guidelines, available
on the Adobe website at http://www.adobe.com/misc/pdfs/TM
GuideforThirdPartiesFinal.pdf. If any portion of the Software is changed, it
cannot be marketed under Adobe's trademarks unless Adobe, in its sole
discretion, approves by a prior writing the quality of the resulting
implementation.

The TeX Users Group shall have the right to evaluate the Software provided by
Adobe.

Then the TeX Users Group (TUG) gave all such rights, irrevocably and in
perpetuity, to any and all interested parties (cf.
http://tug.org/fonts/utopia/LICENSE-utopia.txt).

The Utopia Nova fonts are a modified version of the Heuristica font family
(http://code.google.com/p/evristika), which was last released by Andrey V. Panov
in 2014 in accordance with the conditions of the Adobe/TUG license agreement.

The Heuristica fonts in turn contains glyphs from the Vntopia font family
(http://vntex.sf.net), which was released by Han The Thanh in 2006 also in
accordance with the conditions of the Adobe/TUG license agreement.

The Linguistics Pro font family is a modified version of the Utopia Nova font family
(http://andreas.nolda.org/software.html), which was released by Andreas Nolda
in 2015 under the SIL Open Font License (OFL) – http://scripts.sil.org/ofl.
The Utopia Nova OpenType and Web Open fonts (version 1.12) are a modified version of the Heuristica font family, which in turn is based on the Utopia Type 1 fonts, designed by Robert Slimbach for Adobe and licensed to the TeX Users Group (TUG) for free modification and redistribution. Those Unicode fonts are particularly useful for documents in linguistics, as they include IPA characters as well as many spacing or combining diacritics. In addition, they support various typographic features such as ligatures, proportional figures, etc.; a stylistic set provides longer slashes, matching the parenthesis in height.
The Linguistics Pro font family contains two models of cyrillic glyphs. The base range of the cyrillic glyphs (uni0410:uni044F) represents the modern Bulgarian letterform model. The traditional cyrillic letterform model is included as a local feature for Russian language and as a Stylistic Set 01. Compare to Utopia Nova the encoding in the Linguistics Pro font family is completely rearranged, there are changes in the form of some glyphs and new glyphs are added.
