Merge pull request #217 from Qard/docs-meta-dependencies

Add meta doc summarizing dependencies

locale/en/docs/meta/topics/dependencies.md

@@ -0,0 +1,102 @@
+---
+title: Dependencies
+layout: docs.hbs
+---
+
+# Dependencies
+
+There are several dependencies that Node.js relies on to work the way it does.
+
+- [Libraries](#Libraries)
+  - [V8](#V8)
+  - [libuv](#libuv)
+  - [http-parser](#http-parser)
+  - [c-ares](#c-ares)
+  - [OpenSSL](#OpenSSL)
+  - [zlib](#zlib)
+- [Tools](#Tools)
+  - [npm](#npm)
+  - [gyp](#gyp)
+  - [gtest](#gtest)
+
+## Libraries
+
+### V8
+
+The V8 library provides Node.js with a JavaScript engine, which Node.js
+controls via the V8 C++ API. V8 is maintained by Google, for use in Chrome.
+
+- [Documentation](https://v8docs.nodesource.com/)
+
+### libuv
+
+Another important dependency is libuv, a C library that is used to abstract
+non-blocking I/O operations to a consistent interface across all supported
+platforms. It provides mechanisms to handle file system, DNS, network, child
+processes, pipes, signal handling, polling and streaming. It also includes a
+thread pool for offloading work for some things that can't be done
+asynchronously at the operating system level.
+
+- [Documentation](http://docs.libuv.org/)
+
+### http-parser
+
+HTTP parsing is handled by a lightweight C library called http-parser. It is
+designed to not make any syscalls or allocations, so it has a very small
+per-request memory footprint.
+
+- [Documentation](https://github.com/joyent/http-parser/)
+
+### c-ares
+
+For some asynchronous DNS requests, Node.js uses a C library called c-ares.
+It is exposed through the DNS module in JavaScript as the resolve() family of
+functions. The lookup() function, which is what the rest of core uses, makes
+use of threaded getaddrinfo(3) calls in libuv. The reason for this is that
+c-ares supports /etc/hosts, /etc/resolv.conf and /etc/svc.conf, but not things
+like mDNS.
+
+- [Documentation](http://c-ares.haxx.se/docs.html)
+
+### OpenSSL
+
+OpenSSL is used extensively in both the `tls` and `crypto` modules. It provides
+battle-tested implementations of many cryptographic functions that the modern
+web relies on for security.
+
+- [Documentation](https://www.openssl.org/docs/)
+
+### zlib
+
+For fast compression and decompression, Node.js relies on the industry-standard
+zlib library, also known for its use in gzip and libpng. Node.js uses zlib to
+create sync, async and streaming compression and decompression interfaces.
+
+- [Documentation](http://www.zlib.net/manual.html)
+
+## Tools
+
+### npm
+
+Node.js is all about modularity, and with that comes the need for a quality
+package manager; for this purpose, npm was made. With npm comes the largest
+selection of community-created packages of any programming ecosystem,
+which makes building Node.js apps quick and easy.
+
+- [Documentation](https://docs.npmjs.com/)
+
+### gyp
+
+The build system is handled by gyp, a python-based project generator copied
+from V8. It can generate project files for use with build systems across many
+platforms. Node.js requires a build system because large parts of it — and its
+dependencies — are written in languages that require compilation.
+
+- [Documentation](https://chromium.googlesource.com/external/gyp/+/master/docs/UserDocumentation.md)
+
+### gtest
+
+Native code can be tested using gtest, which is taken from Chromium. It allows
+testing C/C++ without needing an existing node executable to bootstrap from.
+
+- [Documentation](https://code.google.com/p/googletest/wiki/V1_7_Documentation)