+### Logical Design
+
+Folly is a collection of relatively independent components, some as
+simple as a few symbols. There is no restriction on internal
+dependencies, meaning that a given folly module may use any other
+folly components.
+
+All symbols are defined in the top-level namespace `folly`, except of
+course macros. Macro names are ALL_UPPERCASE and should be prefixed
+with `FOLLY_`. Namespace `folly` defines other internal namespaces
+such as `internal` or `detail`. User code should not depend on symbols
+in those namespaces.
+
+Folly has an `experimental` directory as well. This designation connotes
+primarily that we feel the API may change heavily over time. This code,
+typically, is still in heavy use and is well tested.
+
+### Physical Design
+
+At the top level Folly uses the classic "stuttering" scheme
+`folly/folly` used by Boost and others. The first directory serves as
+an installation root of the library (with possible versioning a la
+`folly-1.0/`), and the second is to distinguish the library when
+including files, e.g. `#include <folly/FBString.h>`.
+
+The directory structure is flat (mimicking the namespace structure),
+i.e. we don't have an elaborate directory hierarchy (it is possible
+this will change in future versions). The subdirectory `experimental`
+contains files that are used inside folly and possibly at Facebook but
+not considered stable enough for client use. Your code should not use
+files in `folly/experimental` lest it may break when you update Folly.
+
+The `folly/folly/test` subdirectory includes the unittests for all
+components, usually named `ComponentXyzTest.cpp` for each
+`ComponentXyz.*`. The `folly/folly/docs` directory contains
+documentation.
+
+### What's in it?
+
+Because of folly's fairly flat structure, the best way to see what's in it
+is to look at the headers in [top level `folly/` directory](https://github.com/facebook/folly/tree/master/folly). You can also
+check the [`docs` folder](folly/docs) for documentation, starting with the
+[overview](folly/docs/Overview.md).
+
+Folly is published on Github at https://github.com/facebook/folly
+
+### Build Notes
+
+#### Dependencies
+
+folly requires gcc 4.9+ and a version of boost compiled with C++14 support.