media partners. Polish Deputy Prime Minister Waldemar Pawlak had an opening keynote focusing on the major impact of Open Source on the IT market as a competitive alternative to proprietary solutions and reiterating an opportunity for the Polish IT professionals in deepening its participation in the world-wide IT revolution. Open Source trends were discussed from the point of view of Red Hat by its Vice President Werner Knoblich. During consecutive sessions latest updates about Open Source technologies were presented: middleware: JBoss, RDBMS: PostgreSQL/EnterpriseDB and MySQL as well as Alfresco (software) and Zimbra. Open Source Day 2011 The 4th Open Source Day Conference followed on 22 March 2011 in the Palace of Culture and Science in Warsaw. 500-strong audience arrived. The organization of the event was a performed with the help of 11 technology vendors and service providers as well as 6 media partners. The conference was under the auspices of Ministry of Education. Opening keynotes were provided by Red Hat, EnterpriseDB and Zarafa Vice Presidents. Technical sessions presented latest news from the area of OS Linux, databases, ESB, scalability, monitoring and IT security. Open Source Day 2012 The 5th Open Source Day Conference took place on 8 May 2012 once again in the Palace of Culture and Science. More than 500 guests attended while 14 technology partners provided support to make the event happen. The conference performed under the auspices of the European Commission and Ministry of Administration and Digitization. Opening keynotes were introduced by the representatives of: European Commission, Hewlett Packard, Red Hat and Linux Polska. Technical sessions focused that year on: Enterprise Content Management. It was the first time Big data aspects were discussed, especially in terms of storage capabilities, distributed processing and caching and data virtualization. Open Source Day 2013 The 6th Open Source Day Conference happened on 14 May 2013 this time in the Sheraton Warszawa hotel. 600 audience participated on-site while 1500 watched the event on-line. 9 technology partners supported the event while 5 media partners covered the proceedings. Polish Ministry of Administration and Digitization offered official patronage for the conference. The opening keynote was performed by Michał Boni, Minister of Administration and Digitization and covered the ever growing need for open standards and the opportunities Open Source is providing for Polish IT professionals and entrepreneurs. Open Source Day 2014 The 7th edition of the conference was a 2-day event on 13–14 May 2014 in