IBM has launched the beta of BlueMix, its Cloud Foundry-based PaaS. Understanding what BlueMix, and IBM, do and don’t bring to the table means a bit of a digression into how Cloud Foundry works as a PaaS. Since my blog is usually pretty infrastructure-oriented, I’m guessing that a significant percentage of readers won’t know very much about Cloud Foundry (which I’ll abbreviate as CF).

In CF, users write application code, which they deploy onto CF runtime environments (defined by “buildpacks”) — i.e., programming languages and associated frameworks. When CF is deployed as a PaaS, it will normally have some built-in buildpacks, but users can also add additional ones through a mechanism called buildpacks (which originated at Heroku, a PaaS provider that is not CF-based). CF runs applications in its own “Warden” containers (which are OS-independent), staging the runtime and app code into what it calls “droplets”. These application instances are of a size controlled by the user (developer), and the user chooses how many of them there are. Cloud Foundry does not have native auto-scaling currently.

CF can also expose a catalog of services; these services might or might not be built on top of Cloud Foundry. These services are called “Managed Services”, and they support CF’s Service Broker API, allowing CF to provision those services and bind them to applications. Users can also bind their own service instances, supplying credentials for services that exist outside of CF and that aren’t directly integrated via the Service Broker API. Users of CF can also bind external services that don’t support CF explicitly.

IBM has built its own UI for BlueMix. IBM has said at Pulse that it’s got a new focus on design, and BlueMix shows it — the interface is modern and attractive, and its entire look-and-feel and usability are in stark contrast to, say, its previous SmartCloud Application Services offering. Interacting with the UI is pleasant enough. Most users will probably use the CF command-line tool (CLI), though. Apps are normally deployed using the CLI, unless the customer is using JazzHub (a developer service created out of IBM UrbanCode).

For the BlueMix beta, IBM has created two buildpacks of its own, for Liberty (Java) and Node.js, which it says it has hardened and instrumented. They also supply two community buildpacks, for Ruby on Rails and Ruby Sinatra. As with normal CF, users can supply their own buildpacks, and the open-source CF buildpacks appear to work fine, IBM calls these “runtimes” in the BlueMix portal.

IBM also has a bunch of CF services — “Managed Services” in CF parlance. Some of these are IBM-created, like the DataCache (which is WebSphere eXtreme Scale) and Elastic MQ (WebSphere MQ). Others are labeled “community” and are likely open-source CF service implementations of popular packages like MySQL and MongoDB. As is true with all CF services, the implementation of a service is not necessarily on Cloud Foundry — for instance, one of the services is Cloudant, which is entirely external.

Finally, IBM provides what it calls “boilerplates”, which you can click to create an application with a runtime plus a number of additional services that are bound to the app. The most notable is the “mobile backend starter”, which combines Node.js with a number of mobile-oriented services, like a mobile data store and push notifications.

All in all, the BlueMix beta is a showcase for IBM middleware and other IBM software of interest to developers. IBM has essentially had to SaaS-ify (or PaaS-ify, if you prefer that term) its enterprise software assets to achieve this. Obviously, this is only a sliver of its portfolio, but bringing more software assets into BlueMix is clearly key to its strategy — BlueMix is as much a service catalog as a PaaS in this case.

Broadly, though, it’s very clear that IBM is targeting the enterprise developer, especially the enterprise developer who is currently developing in Java on WebSphere technologies. It’s bringing those developers to the cloud — not targeting cloud-native developers, who are more likely to be drawn to something like AppFog if they’re looking for a CF service. Given that IBM says that it will provide strong support for integrating with existing on-premise applications, this is a strategy that makes sense.

Standard CF constraints apply — limited RAM per application instance (and tight resource limitations in general in BlueMix beta), no writes to the local filesystem, and so forth. Other features that would be value-added, like monitoring and automatic caching of static content, are missing at present.

The short-form way to think of BlueMix beta is “Cloud Foundry with some IBM middleware as a service”. It’s hosted in SoftLayer data centers. Presumably at some point IBM will introduce SLAs for at least portions of the service. It’s certainly worth checking out if you’re a WebSphere shop, and if you’re checking out Cloud Foundry in general, this seems to be a perfectly decent way to do it. There’s solid promise here, and my expectation is that at this stage of the game, PaaS might well be a much stronger play for IBM than IaaS, at least in terms of the ability to articulate the overall value of the IBM ecosystem and make an argument for making a strategic bet on IBM in the cloud.