Apache HBase describes itself as "the Hadoop database," which can be a bit confusing, as Hadoop is typically understood to refer to the popular MapReduce processing framework. But Hadoop is really an umbrella name for an entire ecosystem of technologies, some of which HBase uses to create a distributed, column-oriented database built on the same principles as Google's Bigtable. HBase does not use Hadoop's MapReduce capabilities directly, though HBase can integrate with Hadoop to serve as a source or destination of MapReduce jobs.
Apache Cassandra is a free, open source NoSQL database designed to manage very large data sets (think petabytes) across large clusters of commodity servers. Among many distinguishing features, Cassandra excels at scaling writes as well as reads, and its "master-less" architecture makes creating and expanding clusters relatively straightforward. For organizations seeking a data store that can support rapid and massive growth, Cassandra should be high on the list of options to consider.
MongoDB is certainly one of the most popular open source, document-oriented NoSQL databases. Developed and maintained by 10gen, MongoDB is available in both a free version and a paid-for enterprise version, which adds features such as Kerberos security, SNMP access, and live monitoring features. However, neither the free version nor the enterprise version comes with a management GUI.
Visual Studio is no longer simply an IDE, no longer a place you go just to write and debug C/C++ code. It has long since become something of a development mashup. It's where you go to tackle any task in the development process, regardless of the target. It's where you head to do your LightSwitch development, your SQL Server development, your Web application development, your Windows Azure development, and your ASP.Net or Windows Forms development in C#, F#, VB.Net, and -- oh, yes -- good old Visual C++. Naturally, it's where you build applications for http://www.infoworld.com/category/tags/microsoft-windows-azure and Windows RT.
When you consider the cloud, you typically imagine a realm of deployed, production applications. Zend Developer Cloud (ZDC) adds a twist: ZDC creates a place <em>in</em> the cloud where PHP-based applications can be developed <em>for</em> the cloud. No more developing locally, then deploying into the cloud -- ZDC pushes both into the ether.
Signifying a formless haze of computing power and storage that is somewhere "out there," computerdom's current buzzword is as difficult to get one's arms around as a real cloud. A seemingly limitless pool of processors and memory and disk space, and you just scoop out what you need. Sounds great, doesn't it?
Have you got a few hundred gigabytes of data that need processing? Perhaps a dump of radio telescope data that could use some combing through by a squad of processors running Fourier transforms? Or maybe you're convinced some statistical analysis will reveal a pattern hidden in several years of stock market information? Unfortunately, you don't happen to have a grid of distributed processors to run your application, much less the time to construct a parallel processing infrastructure.