The Apache Software Foundation (ASF) has approved CloudStack as a top-level project (TLP), helping the open-source cloud software effort further establish its independence from Citrix, which acquired the program's codebase in its 2011 purchase of Cloud.com.
"Independence from a single vendor was absolutely required of the community" to become an official Apache project, said Chip Childers, who leads the CloudStack project.
As a TLP, CloudStack has demonstrated that it has a viable and diverse contributor community, as well as an effective governance structure that operates under ASF's meritocratic principles, according to the nonprofit ASF.
A volunteer-led project management committee will oversee CloudStack product releases and community development. ASF, in turn, will provide legal, trademark, infrastructure, conference planning and press support.
CloudStack was designed to run an infrastructure as a service (IaaS), where processing, networking and other capabilities are offered on an as-needed basis. Hosting providers use the software to provide IaaS services to customers, and enterprises are deploying the software to run internal private clouds.
"CloudStack is easy to get up and running quickly, so you can use it for a small, private cloud, just like you can for a large-scale cloud," Childers said. CloudStack is capable of supporting more than 30,000 nodes, spread across different locations.
Although OpenStack has garnered the majority of the attention in the emerging space of IaaS software stacks, CloudStack has been quietly building up a customer roster as well, according to Childers. Managed hosting provider Datapipe uses the software for its own operations, as do disaster-recovery services provider Sungard, domain registrar GoDaddy and hosting provider Softlayer.
VMOps, later renamed Cloud.com, first introduced the CloudStack software in 2009, and released much of the code as open source the following year. Citrix purchased Cloud.com in 2011, and released the rest of the code under open source. In April 2012, Citrix submitted CloudStack to Apache as an incubator project.
While donating a project to an open-source body such as ASF sometimes indicates that the corporate owner no longer has a strategic interest in the program -- such as Oracle did with the OpenOffice project -- this probably was not the case with Citrix. Citrix offers a commercial version of CloudStack and, more generally, the software serves as a cornerstone for the company's cloud strategy.
"Cloud services are fundamentally being built off of open source. Almost everyone in our community believes that," Childers said, pointing to OpenStack, OpenNebula, Eucalyptus and other cloud projects. "We believe that there will be different projects and paths that communities can form around."
The chief challenge with proving CloudStack to be a worthy TLP was to bring in more outside contributors, Childers said. Apache requires potential TLPs to have a diverse community of contributors. Also, many open-source users are wary of software projects controlled by a single corporate entity, fearing the company in charge may lose interest in the software, change it to fit their own purposes or otherwise make it difficult to continue using the program.
When Citrix submitted CloudStack, most of the contributors to the code base were the company's own engineers. Since then, the project has garnered more help, much from users of the software, Childers said.
To date, 164 contributors have made 16,795 commits to the code base, representing 1,161,748 lines of code, according to the Black Duck Ohloh repository of statistics about open-source projects. The project now has 30 committers -- those who can make changes directly to the code base -- including non-Citrix engineers from service providers and software vendors such as Basho, Betterservers, Backbone Technology and Usablenet.
"A lot of the contributors [now] are users of the software. They want to add new features or improve certain areas," Childers said. In particular, CloudStack has seen a lot of interest and code contributions from hosting providers in Europe and Asia. "There are very strong communities around CloudStack in Japan and Korea," Childers said.
At present, the group is working on a new version of the software, version 4.1, which will be available in the very near future. The next release will offer the ability to split a cloud deployment across different regions, similar to how Amazon Web Services (AWS) offers its customers the ability to specify in which specific regional zones their jobs can operate.
CloudStack 4.1 will also offer a new event framework, which should make it easy for administrators to manage operations. The software has been integrated with Nicera software-defined networking (SDN) software, so CloudStack users can control layer 3 routing, in addition to layer 2 routing. It will also couple with Amazon's S3 (Simple Storage Service) and S3-compatible storage services, which will provide a secondary storage for users to keep data volumes, snapshots and all other preparatory materials needed to run virtual workloads.
The ASF oversees more than 100 different open-source projects, including such widely used programs as Apache Hadoop, the Tomcat Web servlet container, the OpenOffice office suite, the Cassandra NoSQL data store and the HTTP server.
CloudStack is available under an Apache License v2.0 license.