Yeoman vs Slush

Yeoman has an active community with new generators being created at a rapid pace. Because of the momentum behind the community, you can expect good support and adoption for new tools and frameworks promptly after they come out.

Yeoman generators allow you to quickly set up a new project. Invoked with the scaffolding tool 'yo' they provide a boilerplate & tooling selection. There are over 1000 generators, including generators for ember, angular & backbone, to choose from, the majority of which are community maintained.

Yeoman supports both major build systems - Grunt and Gulp. These build systems will help you automate tasks such as minification & concatenation of files, running tests, deploying and live-updating your webpage among many others.

Yeoman is free, open source and licensed under BSD.

Yeoman supports both Bower and npm, and is flexible in regard to tools to allow it to work with a wider range of project requirements.

Yeoman wants webapp development to be more standardized under the "Yeoman workflow" banner. As such it encourages the use of a specific combination of tools - a scaffolding tool (yo), a build tool (grunt, gulp, etc) and a package manager (bower, npm).

Yeoman's scaffolding system allows generators to rely on other generators allowing for better code reuse and standardization between generators that use a common sub-component.

As a command line tool it works on OS X, Linux & Windows.

Yeoman doesn't just scaffold your project, but also helps you integrate with your package manager directly, so you can manage your entire project with it.

Developers can also create their own Yeoman generator which are practically plugins with which Yeoman works. Generators are basically Node.js modules and can be created just like any other Node module.

There is also a very detailed and useful guide on how to create a generator on the Yeoman official website.

Slush scaffolds can use Inquirer to get CLI input for setting up projects.

Because Slush is built around streams and designed to work best with Gulp. It allows you to get the benefits of a streaming build system without having to manage the components yourself.

Because Slush is built on Gulp which puts code before configuration, scaffolding can be done in a simpler more straightforward way. Creating scaffolding through configuration requires more knowledge about the scaffold's specific implementation and remembering documentation, whereas doing it in code is more self explanatory and requires less domain knowledge to get others up to speed.

Because all Slush scaffolds share the commonality of streams, it's easier to combine them through that common interface. With configuration based workflow wrappers, different components may have specific implementations that can cause problems with interoperability. With streams, there's better encapsulation of functionality, making it harder to mess up a scaffold leading to better compatibility.

Slush has a well cataloged collection of scaffolds created for it by the community, providing a large collection of workflows prebuilt for almost any task you might want to perform.

You can view the list of generators here.