We're well out of the Web 2.0 days, and firmly in the world of SaaS and PaaS, but what does it mean?
What is Software as a Service (SaaS)?
SaaS or Software as a Service is a model of software delivery when all the software and data is stored in the "cloud". A good example here is Google Docs, where historically users would've used Micrsoft Word or WordPerfect and stored files locally, Google Docs runs on the web, and all documents are store in Google Drive. 37 Signals (before rebranding as Basecamp) have become famous for their web based SaaS apps such as Basecamp, Highrise and Backpack. Each service requires a small monthly free for access to a different service. The development of Basecamp spawned the development of Ruby on Rails, making it a fantastic platform for building SaaS apps.
The SaaS business model is great for all, it means an ongoing income for the company behind the application, but no need for a large outlay in cost for the user. Updates can quickly and easily rolled out to the user, often without any downtime, and also at no extra cost.
What is Platform as a Service (PaaS)?
SaaS or Software as a Service is a model of software delivery when all the software and data is stored in the "cloud". Traditionally a developer or agency would purchase a dedicated or virtual server and set that up as needed. With the advent of "Cloud Computing" server resources could quickly and easily be hired and fired allowing for a more flexible and scalable model. From here PaaS was born with companies such Engine Yard and Heroku building upon these cloud platforms to offer a system where applications could be deployed in seconds with little or no effort and configuration, there also had the scalability of the Cloud platforms they were built on.
Using SaaS and PaaS
As the only Heroku partner in Wales, UK, we are proud to use their PaaS platform, deploying most client's applications to a Heroku environment. Many of these applications would fall under the SaaS category, whether they are for private use within a company, or public use for a monthly fee. As mentioned earlier Ruby on Rails is a great platform for SaaS applications, however in Sinatra Cookbook it's discussed how to build a SaaS application with Sinatra, integrating with Stripe as the payment gateway.