What exactly is Rake?

In simple terms, what does Rake do? What purposes does it have? I understand it's a build tool but I'm looking a bit more detail. (For a simpleton.)

These answers assume you know what a DSL is, or are familiar with Make or Ant. If that's not the case, here's a (perhaps grossly oversimplified answer):

Rake is a tool you can use with Ruby projects. It allows you to use ruby code to define "tasks" that can be run in the command line.

Rake can be downloaded and included in ruby projects as a ruby gem.

Once installed, you define tasks in a file named "Rakefile" that you add to your project.

We call it a "build tool" because Rake comes with some libraries that make it easy to do tasks that are common during the build/deploy process, like file operations (creating, deleting, renaming, & moving files), publishing sites via FTP/SSH, and running tests.

For more information, here's the project documentation: http://rake.rubyforge.org/

Try Martin Fowler's article on Rake for more information:

http://martinfowler.com/articles/rake.html

His pre-amble is:

Rake is a build language, similar in purpose to make and ant. Like make and ant it's a Domain Specific Language, unlike those two it's an internal DSL programmed in the Ruby language. In this article I introduce rake and describe some interesting things that came out of my use of rake to build this web site: dependency models, synthesized tasks, custom build routines and debugging the build script.

There is more information available on or linked from the project's home page as well:

http://rake.rubyforge.org/

Rake lets you execute Ruby code through a nice namespace api. An example is rake db:migrate. You can run tasks automatically before and after other tasks. That is all.