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+# How to Contribute to Abseil
+
+We'd love to accept your patches and contributions to this project. There are
+just a few small guidelines you need to follow.
+
+NOTE: If you are new to GitHub, please start by reading [Pull Request
+howto](https://help.github.com/articles/about-pull-requests/)
+
+## Contributor License Agreement
+
+Contributions to this project must be accompanied by a Contributor License
+Agreement. You (or your employer) retain the copyright to your contribution,
+this simply gives us permission to use and redistribute your contributions as
+part of the project. Head over to <https://cla.developers.google.com/> to see
+your current agreements on file or to sign a new one.
+
+You generally only need to submit a CLA once, so if you've already submitted one
+(even if it was for a different project), you probably don't need to do it
+again.
+
+## Contribution Guidelines
+
+Potential contributors sometimes ask us if the Abseil project is the appropriate
+home for their utility library code or for specific functions implementing
+missing portions of the standard. Often, the answer to this question is "no".
+We’d like to articulate our thinking on this issue so that our choices can be
+understood by everyone and so that contributors can have a better intuition
+about whether Abseil might be interested in adopting a new library.
+
+### Priorities
+
+Although our mission is to augment the C++ standard library, our goal is not to
+provide a full forward-compatible implementation of the latest standard. For us
+to consider a library for inclusion in Abseil, it is not enough that a library
+is useful. We generally choose to release a library when it meets at least one
+of the following criteria:
+
+*   **Widespread usage** - Using our internal codebase to help gauge usage, most
+    of the libraries we've released have tens of thousands of users.
+*   **Anticipated widespread usage** - Pre-adoption of some standard-compliant
+    APIs may not have broad adoption initially but can be expected to pick up
+    usage when it replaces legacy APIs. `absl::from_chars`, for example,
+    replaces existing code that converts strings to numbers and will therefore
+    likely see usage growth.
+*   **High impact** - APIs that provide a key solution to a specific problem,
+    such as `absl::FixedArray`, have higher impact than usage numbers may signal
+    and are released because of their importance.
+*   **Direct support for a library that falls under one of the above** - When we
+    want access to a smaller library as an implementation detail for a
+    higher-priority library we plan to release, we may release it, as we did
+    with portions of `absl/meta/type_traits.h`. One consequence of this is that
+    the presence of a library in Abseil does not necessarily mean that other
+    similar libraries would be a high priority.
+
+### API Freeze Consequences
+
+Via the
+[Abseil Compatibility Guidelines](https://abseil.io/about/compatibility), we
+have promised a large degree of API stability. In particular, we will not make
+backward-incompatible changes to released APIs without also shipping a tool or
+process that can upgrade our users' code. We are not yet at the point of easily
+releasing such tools. Therefore, at this time, shipping a library establishes an
+API contract which is borderline unchangeable. (We can add new functionality,
+but we cannot easily change existing behavior.) This constraint forces us to
+very carefully review all APIs that we ship.
+
+
+## Coding Style
+
+To keep the source consistent, readable, diffable and easy to merge, we use a
+fairly rigid coding style, as defined by the
+[google-styleguide](https://github.com/google/styleguide) project. All patches
+will be expected to conform to the style outlined
+[here](https://google.github.io/styleguide/cppguide.html).
+
+## Guidelines for Pull Requests
+
+*   If you are a Googler, it is preferable to first create an internal CL and
+    have it reviewed and submitted. The code propagation process will deliver
+    the change to GitHub.
+
+*   Create **small PRs** that are narrowly focused on **addressing a single
+    concern**. We often receive PRs that are trying to fix several things at a
+    time, but if only one fix is considered acceptable, nothing gets merged and
+    both author's & review's time is wasted. Create more PRs to address
+    different concerns and everyone will be happy.
+
+*   For speculative changes, consider opening an [Abseil
+    issue](https://github.com/abseil/abseil-cpp/issues) and discussing it first.
+    If you are suggesting a behavioral or API change, consider starting with an
+    [Abseil proposal template](ABSEIL_ISSUE_TEMPLATE.md).
+
+*   Provide a good **PR description** as a record of **what** change is being
+    made and **why** it was made. Link to a GitHub issue if it exists.
+
+*   Don't fix code style and formatting unless you are already changing that
+    line to address an issue. Formatting of modified lines may be done using
+   `git clang-format`. PRs with irrelevant changes won't be merged. If
+    you do want to fix formatting or style, do that in a separate PR.
+
+*   Unless your PR is trivial, you should expect there will be reviewer comments
+    that you'll need to address before merging. We expect you to be reasonably
+    responsive to those comments, otherwise the PR will be closed after 2-3
+    weeks of inactivity.
+
+*   Maintain **clean commit history** and use **meaningful commit messages**.
+    PRs with messy commit history are difficult to review and won't be merged.
+    Use `rebase -i upstream/master` to curate your commit history and/or to
+    bring in latest changes from master (but avoid rebasing in the middle of a
+    code review).
+
+*   Keep your PR up to date with upstream/master (if there are merge conflicts,
+    we can't really merge your change).
+
+*   **All tests need to be passing** before your change can be merged. We
+    recommend you **run tests locally** (see below)
+
+*   Exceptions to the rules can be made if there's a compelling reason for doing
+    so. That is - the rules are here to serve us, not the other way around, and
+    the rules need to be serving their intended purpose to be valuable.
+
+*   All submissions, including submissions by project members, require review.
+
+## Running Tests
+
+If you have [Bazel](https://bazel.build/) installed, use `bazel test
+--test_tag_filters="-benchmark" ...` to run the unit tests.
+
+If you are running the Linux operating system and have
+[Docker](https://www.docker.com/) installed, you can also run the `linux_*.sh`
+scripts under the `ci/`(https://github.com/abseil/abseil-cpp/tree/master/ci)
+directory to test Abseil under a variety of conditions.
+
+## Abseil Committers
+
+The current members of the Abseil engineering team are the only committers at
+present.
+
+## Release Process
+
+Abseil lives at head, where latest-and-greatest code can be found.