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+## Overview
+
+MSpec is a specialized framework that is syntax-compatible with RSpec 2 for
+basic things like `describe`, `it` blocks and `before`, `after` actions.
+MSpec contains additional features that assist in writing specs for
+Ruby implementations in [ruby/spec](https://github.com/ruby/spec).
+
+MSpec attempts to use the simplest Ruby language features so that beginning
+Ruby implementations can run the Ruby specs. For example, no file from the
+standard library or RubyGems is necessary to run MSpec.
+
+MSpec is not intended as a replacement for RSpec. MSpec attempts to provide a
+subset of RSpec's features in some cases and a superset in others. It does not
+provide all the matchers, for instance.
+
+However, MSpec provides several extensions to facilitate writing the Ruby
+specs in a manner compatible with multiple Ruby implementations.
+
+  1. MSpec offers a set of guards to control execution of the specs. These
+     guards not only enable or disable execution but also annotate the specs
+     with additional information about why they are run or not run.
+
+  2. MSpec provides a different shared spec implementation specifically
+     designed to ease writing specs for the numerous aliased methods in Ruby.
+
+  3. MSpec provides various helper methods to simplify some specs, for
+     example, creating temporary file names.
+
+  4. MSpec has several specialized runner scripts that includes a
+     configuration facility with a default project file and user-specific
+     overrides.
+
+  5. MSpec support "tagging", that is excluding specs known as failing on
+     a particular Ruby implementation, and automatically adding and removing tags
+     while running the specs.
+
+## Requirements
+
+MSpec requires Ruby 2.6 or more recent.
+
+## Bundler
+
+A Gemfile is provided. Use Bundler to install gem dependencies. To install
+Bundler, run the following:
+
+```bash
+gem install bundler
+```
+
+To install the gem dependencies with Bundler, run the following:
+
+```bash
+ruby -S bundle install
+```
+
+## Development
+
+Use RSpec to run the MSpec specs. There are no plans currently to make the
+MSpec specs runnable by MSpec: https://github.com/ruby/mspec/issues/19.
+
+After installing the gem dependencies, the specs can be run as follows:
+
+```bash
+ruby -S bundle exec rspec
+```
+
+To run an individual spec file, use the following example:
+
+```bash
+ruby -S bundle exec rspec spec/helpers/ruby_exe_spec.rb
+```
+
+## Documentation
+
+See [CONTRIBUTING.md](https://github.com/ruby/spec/blob/master/CONTRIBUTING.md) in ruby/spec
+for a list of matchers and how to use `mspec`.
+
+## Source Code
+
+See https://github.com/ruby/mspec
+
+## License
+
+See the LICENSE in the source code.