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# Use of Python
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Meson is implemented in Python. This has both positive and negative
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sides. The main thing people seem to be mindful about is the
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dependency on Python to build source code. This page discusses various
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aspects of this problem.
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# Dependency hell
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There have been many Python programs that are difficult to maintain on
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multiple platforms. The reasons come mostly from dependencies. The
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program may use dependencies that are hard to compile on certain
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platforms, are outdated, conflict with other dependencies, not
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available on a given Python version and so on.
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Meson avoids dependency problems with one simple rule: Meson is not
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allowed to have any dependencies outside the Python basic library. The
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only thing you need is Python 3 (and possibly Ninja).
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## Reimplementability
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Meson has been designed in such a way that the implementation language
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is never exposed in the build definitions. This makes it possible (and
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maybe even easy) to reimplement Meson in any other programming
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language. There are currently no plans to reimplement Meson, but we
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will make sure that Python is not exposed inside the build
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definitions.
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## Cross platform tooling
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There is no one technical solution or programming language that works
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natively on all operating systems currently in use. When Autotools was
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designed in the late 80s, Unix shell was available pretty much
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anywhere. This is no longer the case.
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It is also the case that as any project gets larger, sooner or later
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it requires code generation, scripting or other tooling. This seems to
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be inevitable. Because there is no scripting language that would be
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available everywhere, these tools either need to be rewritten for each
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platform (which is a lot of work and is prone to errors) or the
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project needs to take a dependency on _something_.
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Any project that uses Meson (at least the current version) can rely on
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the fact that Python 3 will always be available, because you can't
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compile the project without it. All tooling can then be done in Python
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3 with the knowledge that it will run on any platform without any
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extra dependencies (modulo the usual porting work). This reduces
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maintenance effort on multiplatform projects by a fair margin.
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