Being a fork of Wine, Proton maintains very similar compatibility with Windows applications as its upstream counterpart. In addition to the official whitelist, a very large portion of the Windows catalog is reportedly compatible, albeit unofficially, with Proton. The user can optionally force use of Proton for a specific title, even if a Linux version already exists.
To minimize license proliferation and license incompatibilities in the FOSS ecosystem, some organizations (the Free Software Foundation, for instance) and individuals (David A. Wheeler), argue that compatibility with the widely used GPL is an important feature of software licenses. Many of the most common free-software licenses, especially the permissive licenses, such as the original MIT/X license, BSD licenses (in the three-clause and two-clause forms, though not the original four-clause form), MPL 2.0, and LGPL, are GPL-compatible. That is, their code can be combined with a program under the GPL without conflict, and the new combination would have the GPL applied to the whole (but the other license would not so apply).
Hardware compatibility can refer to the compatibility of computer hardware components with a particular CPU architecture, bus, motherboard or operating system. Hardware that is compatible may not always run at its highest stated performance, but it can nevertheless work with legacy components. An example is RAM chips, some of which can run at a lower (or sometimes higher) clock rate than rated. Hardware that was designed for one operating system may not work for another, if device or kernel drivers are unavailable. For example, much of the hardware for Mac OS X is proprietary hardware with drivers unavailable for use in operating systems such as Linux.
Software compatibility can refer to the compatibility that a particular software has running on a particular CPU architecture such as Intel or PowerPC. Software compatibility can also refer to ability for the software to run on a particular operating system. Very rarely is a compiled software compatible with multiple different CPU architectures. Normally, an application is compiled for different CPU architectures and operating systems to allow it to be compatible with the different system. Interpreted software, on the other hand, can normally run on many different CPU architectures and operating systems if the interpreter is available for the architecture or operating system. Software incompatibility occurs many times for new software released for a newer version of an operating system which is incompatible with the older version of the operating system because it may miss some of the features and functionality that the software depends on.
Several blocks of Unicode characters include either entirely or almost entirely all compatibility characters (U+F900–U+FFEF except for the nonchars). The compatibility blocks contain none of the semantically distinct compatibility characters with only one exception: the rial currency symbol (﷼ U+FDFC) so the compatibility decomposable characters in the compatibility blocks fall unambiguously into the set of discouraged characters. Unicode recommends authors use the plain text compatibility decomposition equivalents instead and complement those characters with rich text markup. This approach is much more flexible and open-ended than using the finite set of circled or enclosed alphanumerics to give just one example.
Several other characters in these blocks have no compatibility mapping but are clearly intended for legacy support:
Alphabetic Presentation Forms (1) # Hebrew Point Judeo-Spanish Varika (U+FB1E): ﬞ. This is a glyph variant of Hebrew Point Rafe (U+05BF): ֿ, though Unicode provides no compatibility mapping.
These thirteen characters are not compatibility characters, and their use is not discouraged in any way. However, U+27EAF 𧺯, the same as U+FA23 﨣, is mistakenly encoded in CJK Unified Ideographs Extension B. In any event, a normalized text should never contain both U+27EAF 𧺯 and U+FA23 﨣; these code points represent the same character, encoded twice.
The Hindu/Indian system of examining compatibility based on horoscopes of the aspirant couple is unique. The fundamental concept of matching horoscopes emanates from constellations occupied by the Ascendant/Lagna (Lagna) at the time of births of bride and bridegroom. Individuals inherit qualities of the birth constellation. Various constellations represent different nature in respect of their casts, animals presented by them, sex, Gana (God/man/demon), humour, birds ruled, primordial elements, Gotra, directions ruled, consonants and vowels, mutual harmony and repulsion with certain stars, beneficence to the other stars by virtue of mutual distance etc.
Unfortunately, there are a small number of characters even within the compatibility blocks that themselves are not compatibility characters and therefore may confuse authors. The "Enclosed CJK Letters and Months" block contains a single non-compatibility character: the 'Korean Standard Symbol' (㉿ U+327F). That symbol and 12 other characters have been included in the blocks for unknown reasons. The "CJK Compatibility Ideographs" block contains these non-compatibility unified Han ideographs:
In another system, only eight of these factors are given importance and are assigned numeric values - Varna (1 point), Vashya (2 Points), Tara (3 points), Yoni (4 points), Graha Maitri (5 points), Gana (6 points), Bhakoota (7 points) and Nadi (8 points). The total of these factors adds up to 36 points and a horoscope is considered to be matched only if the compatibility score is more than 18
The Common Development and Distribution License (CDDL)—a weak copyleft license in-between the GPL license and BSD/MIT permissive licenses—tries to address license compatibility problems by permitting, without re-licensing, the mixing of CDDL-licensed source-code files with source-code files under other licenses by providing that the resulting binary can be licensed and sold under a different license as long as the source code is still available under CDDL.
An example of a license that has excellent compatibility with other FOSS licenses is the Artistic License 2.0, due to its re-licensing clause which allows redistribution of the source code under any other FOSS license. "You may Distribute your Modified Version as Source (either gratis or for a Distributor Fee, and with or without a Compiled form of the Modified Version) […] provided that you do at least ONE of the following: […](c) allow anyone who receives a copy of the Modified Version to make the Source form of the Modified Version available to others under
The compatibility problem for small strains can be stated as follows.
License compatibility between a copyleft license and another license is often only a one-way compatibility, making the copyleft license (GPL, and most other copyleft licenses) incompatible with proprietary commercial licenses, as well as with many non-proprietary licenses. This "one-way compatibility" characteristic has been criticized by the Apache Foundation, which licenses under the more permissive Apache license, such non-copyleft licenses being often less complicated and making for better license compatibility.
The problem of compatibility in continuum mechanics involves the determination of allowable single-valued continuous fields on simply connected bodies. More precisely, the problem may be stated in the following manner.
For solids in which the deformations are not required to be small, the compatibility conditions take the form :where is the deformation gradient. In terms of components with respect to a Cartesian coordinate system we can write these compatibility relations as :This condition is necessary if the deformation is to be continuous and derived from the mapping (see Finite strain theory). The same condition is also sufficient to ensure compatibility in a simply connected body.
The compatibility conditions in linear elasticity are obtained by observing that there are six strain-displacement relations that are functions of only three unknown displacements. This suggests that the three displacements may be removed from the system of equations without loss of information. The resulting expressions in terms of only the strains provide constraints on the possible forms of a strain field.
The compatibility condition for the deformation gradient is obtained directly from the above proof by observing that :Then the necessary and sufficient conditions for the existence of a compatible field over a simply connected body are :
The rich text compatibility characters comprise 1,451 of the 5,402 compatibility characters. These include all of the compatibility characters marked with keywords <circle> and <font> (except three listed in the semantically distinct below); 11 spaces variants from the <compat> and canonical characters; and some of the keyword <superscript> and <subscript> from the "Superscripts and Subscripts" block.