The year 2012 was one of the most successful year for Linux and open source technologies with Red Hat scoring more than a billion dollars in revenues and Google's Android became the dominant player in the mobile space. The year 2013 already seems promising for the free and open source technologies and it seems the world will see more and more open source technologies and standards dominating the IT landscape. Here is my take on the top 5 open source technologies to look out for in 2013.
Novacut: Video editing has been one of the weak points for Linux platform, but there is a promising project which may change it. Novacut is a real-time collaboration video editing software which aims to compete with existing video editors include AVID, Adobe Premiere, Apple Final Cut Pro, and of course Lightworks (which is in the process of going somewhat open source and porting to Linux).
OpenPhoto: Openphoto is an open source application with for photo sharing. You can store your photos on all the popular storing places like Amazon S3, Dropbox, box.net, dreamhost (dreamobjects) and get all the web interface to manage it vai Openphoto. It has a feature rich API and supports PHP/Java/Python/Ruby. Openphoto can be used as a standalone hosted application on your own server or you can get free or pro account from their enterprise website.
ownCloud: ownCloud is one of the most important open source projects in the age of so-called cloud computing. Since governments are becoming increasingly powerful and clouds give them direct access to your data, it's very important that users become the 'owner' of their clouds and not some 3rd parties. Some cases where Microsoft blocked access to SkyDrive also raises concerns that your data is no more 'private' when uploaded to the 'clouds' of companies like Microsoft.
ownCloud gives you universal access to your files through a web interface or WebDAV. It also provides a platform to easily view & sync your contacts, calendars and bookmarks across all your devices and enables basic editing right on the web. Installation has minimal server requirements, doesn’t need special permissions and is quick. ownCloud is extendable via a simple but powerful API for applications and plugins.
HTML5: The open web was held hostage to many proprietary and insecure technologies such as Adobe Flash for almost a decade now; that's changing with HTML5. HTML5 is a markup language for structuring and presenting content for the World Wide Web and a core technology of the Internet. It is the fifth revision of the HTML standard (created in 1990 and standardized as HTML4 as of 1997) and, as of December 2012, is a W3C Candidate Recommendation. Its core aims have been to improve the language with support for the latest multimedia while keeping it easily readable by humans and consistently understood by computers and devices (web browsers, parsers, etc.). HTML5 is intended to subsume not only HTML 4, but XHTML 1 and DOM Level 2 HTML as well.