Sustained growth of the impact factors of MDPI open access journals.

Following the tradition established during the past two years, we are pleased to report the newly released Impact Factors of MDPI open access journals by the means of an editorial. This year's edition of the Journal Citation Reports (JCR), which is published annually by Thomson Reuters, includes seven journals published by MDPI, including three that received their first official Impact Factors--Energies, Entropy, and more surprisingly Viruses--the latest with citation data from 2009 only. We are pleased to announce that the continued growth in Impact Factors reported during the past two years has been sustained, and Impact Factors of MDPI journals continue on a growth path. Table 1 reports the latest Impact Factors for 2010. Figure 1 graphically depicts the evolution of the Impact Factors for the four MDPI open access journals that have received Impact Factors in the past. Table 2 reports the ranking of the MDPI journals within the subject categories of the Science Citation Index Expanded (SCIE).