We are pleased to report the continued increase of Impact Factors of MDPI journal in 2009 (see Figure 1 and Table 1).

Figure 1. Impact Factor Progress 2005-2009. Click here to enlarge figure

As noted in a similar Editorial published in June 2009, the Impact Factors of MDPI journals havebeen steadily recovering since the inception of the full Open Access publishing policy in early 2007 [1]. We are pleased to see that all journals now have an Impact Factor much higher than 1. In 2011 the Journal Citation Report (JCR) will include the first official Impact Factor of Entropy, and in 2012, the International Journal of Environmental Research and Public Health will be included for the first time. Nevertheless, we are already able to compute a preliminary impact factor of approximately 1.4 for Entropy [2].

Table 1. Impact Factors of four MDPI journals (adapted from the Journal Citation Report (JCR), Edition 2009, Copyright 2010 by Thomson Reuters). Click here to enlarge table