AppFog vs dotCloud: What are the differences?

What is AppFog? Simple PaaS for Java, Python, Node, .Net, Ruby, PHP, MySQL, Mongo, and PostgreSQL. AppFog provides the infrastructure web developers need to build apps without worrying about IT tasks or having to wait days to get servers ready for writing code. AppFog’s web application technologies include PHP, NodeJS, Ruby, Python, Java, .NET, MySQL, and PostgreSQL.

What is dotCloud? Deploy, manage and scale any web app. Build your ideal application stack by combining powerful cloud services. Experiment for free, then go live and only pay for what you need. dotCloud enables developers and IT organizations to deploy, manage and scale their applications with unprecedented ease and flexibility by assembling and customizing powerful pre-configured stacks and services.

AppFog and dotCloud can be categorized as "Platform as a Service" tools.

Some of the features offered by AppFog are:

• Launches fast, runs fast- Varnish Cache and op-code caching run applications with less server load and accelerated performance.
• Reduces ops work- No more configuring servers, firewalls, Apache, security, or installing frameworks.
• Plays well with any SCM- Versioning is critical. AppFog is compatible with code management systems like git, svn, and mercurial.

On the other hand, dotCloud provides the following key features:

• Develop faster- Don’t waste time with servers. Just select the services you need, combine them in a stack, and get back to writing code. It’s like playing lego!
• Don't worry about ops- We keep your app running 24/7 with built-in load-balancing, monitoring and failover. Scale in seconds to handle surges in traffic - and only pay for what you need.
• Not just for throw-away apps- Create maintainable, future-proof applications with a service-oriented architecture. Build custom services and network topologies. Need custom support, pricing or SLAs? We do that too.