Mashup Basics: Three for the Money

There's some disagreement in the industry about what, exactly, constitutes a mashup. While they clearly involve integrating data from one or more sources, that doesn't nec-essarily require special tools. It can, in principle, be done anywhere, using any kind of programming language. Kapow Technologies told us mashups differ from other kinds of application integration in that the end user has some control. Oracle says that enter-prise mashups involve both internal and external data sources. Nexaweb Technologies believes mashups are defined as Web-based, while Curl says they happen on the client rather than the server.

However, nearly everyone agrees that mashups can be divided into three broad types: presentation, data and logic.

Presentation Mashups

A presentation mashup is the simplest, bringing information from more than one source together into a common user interface. Web portals can be thought of as presen-tation mashups, though internal enterprise portals are still fairly static compared with public Web sites, like iGoogle and My Yahoo, that let users choose the features that appear on their home pages. Because presentation mashups involve little real integra-tion, creating them usually means simply dragging and dropping pre-built widgets or choosing among RSS feeds.

All enterprise mashup platforms offer presentation functionality, claiming to make in-ternal portals as customizable as Google and Yahoo. The only real advantage here is employee satisfaction—which, in some organizations, is important to IT's long-term relevance. They can also improve security and privacy if employees would otherwise be uploading content to Web sites or exposing RSS feeds through the firewall.

Data Mashups
The next step is the data mashup, which means extracting data from multiple sources and combining it. The goal is easier access: Instead of combing through multiple data-bases, users can query several databases at once, both saving time and enabling more cross-referencing and comparison. The most well-known examples are the map-based mashups popping up like mushrooms on the Web: Most mix geographical data with something else, whether Wi-Fi hotspot locations, house prices or crime statistics.Data mashups can be much harder to create than those at the presentation layer, as the process to date usually involves at least some programming. However, Yahoo's Pipes offers a programming-free way to build data mashups on public sites, and vendors like Coghead aim to make them accessible to non-IT staff too, thanks to relatively straight-forward visual development environments. Data mashups can add real value: A map for potential customers on the corporate Web site, or a portal that mixes a CRM and accounting application for customer service reps.

Logic Mashups
Logic mashups are potentially the most complex, always involving programming. They connect two or more applications, automating certain tasks, and include aware-ness of workflow. The most well-known examples are comparison-shopping sites like Kayak and Wingmap, which use Web services to retrieve fares and then book flights at multiple online travel agencies.

In the enterprise, logic mashups overlap with traditional workflow apps, such as In-tegrify and WorkPoint, and with the composite applications long touted as the main benefit of SOA. The difference is that traditional workflow applications tend to be fo-cused on a single task, such as supply ordering or expense approvals, whereas mash-ups should enable rapid customization and adaptation, letting one platform serve as the basis for multiple tasks. Some vendors such as Serena Software even aim to make logic-based mashups accessible to non-IT staff, though usually not everyone in an or-ganization.

The overlap with SOA is much grayer for logic mashups than the other two catego-ries. Client-side mashups compete with server-side orchestration technologies such as BPEL (Business Process Execution Language), but that hasn't stopped large enterprise SOA vendors IBM, Microsoft, BEA, Sun and Oracle from embracing enterprise mashups. The reason is that, like BPEL, mashups depend on standardized Web ser-vices and APIs, all of which SOA is aimed at making available.

This doesn't mean that mashups depend on SOA. In a recent survey, nearly two thirds of enterprises that use browser-based mashups have done so without SOA, mostly using Microsoft server platforms and .NET. And one of the biggest advantages of mashup technology is the low barrier to entry, with many applications using free services on the Internet.0