Xeround is a SQL Database as a Service vendor which is aggressively targeting the PaaS vendors as a channel. It has established relationships with Heroku, Engine Yard, AppFog and AppHarbour so that if you subscribe to their PaaS you are offered an upgrade to their bundled MySQL database services through a service from Xeround.
In addition to PaaS there is a class of vendors who provide external services to PaaS through “marketplaces” that the vendor sets up. We refer to these generically as Application Services as a Service (ASaaS). The stakes are potentially huge – the PaaS takes over from the Operating System as the dominant factor in the purchasing decision for server-side technology. We’re not saying it definitely will happen, but it might.
As mentioned in a number of posts, there is a clear trend away from Platform-specific PaaS (where you write your application to the platform) and Language-Specific PaaS (which provide support to one or possibly a couple of languages) to Universal PaaS, which is capable of supporting any language and any platform. There’s a little bit of a gray area, but we would include ActiveState Stackato, AppFog, dotCloud, GigaSpaces Cloudify, Red Hat OpenShift, Salesforce Heroku, Uhuru Software AppCloud and VMWare CloudFoundry in this category. These vendors differentiate themselves by providing a broad range of Application Services or Application Lifecycle Services.