Beyond websites: PaaS and web applications
Klebos is anticipating that most web applications will migrate to "platforms" from shared hosting.
The move from shared hosting on a single web-server to virtual machines went unnoticed by most customers of web hosting services: they still had to upload files using FTP and they could include dynamic web pages programmed in PHP or ASP. Every now and then, the server farm company upgraded the operating system and webserver for new customers, but generally left old sites alone until they died of neglect or were forcibly upgraded (which broke many websites and they had to be manually fixed).
Today, the speed of operating system, web server and web application language updates is such that this approach no longer works, and is increasingly non-viable: we need "erosion resistant" systems. A web hosting company (such as Klebos) cannot keep pace with migrating websites, event when the operating system patches are managed by the server farm. It is time to step up a level.
That new level is Paas: Platform as a Service, such as Google App Engine or Heroku.
"In traditional server-based deployments, the app's sourcecode, config, processes, and logs are deeply entangled with the underlying server setup. The app touches the OS and network infrastructure in a hundred implicit places, from system library versions to hardcoded IP addresses and hostnames. This makes anti-erosion tasks like moving the app to a new cluster of servers a highly manual, time-consuming, and error-prone procedure.
On Heroku, the app and the platform it runs on are strongly separated. Unlike a Linux or BSD distribution, which gets major revisions every six, twelve, or eighteen months, Heroku's infrastructure is improving continuously. We're making things faster, more secure, more robust against failure. We make these changes on nearly a daily basis, and we can do so with the confidence that this will not disturb running apps. "
"In the modern era, software is commonly delivered as a service: called web apps, or software-as-a-service. The twelve-factor app is a methodology for building software-as-a-service apps: www.12factor.net/.