financial difficulty. Two conferences (ISMB 2003, in Brisbane and ISMB 2006, in Fortaleza) had drastically reduced numbers of participants due to their location, with a corresponding reduction in income. To allow more delegates to attend, it was decided to limit conference locations to North America and Europe. In January 2007, ISMB and ECCB agreed to hold joint conferences in Europe every other year, beginning with ISMB/ECCB 2007. ISMB would be held in North America in the years between joint meetings. , this pattern has been confirmed to continue until at least 2019. ISMB/ECCB 2007 (held in Vienna, Austria) marked the first conference for which ISCB took full responsibility for organising. Vienna became the first city to host ISMB twice with ISMB/ECCB 2011. This 'return visit' was an experiment intended to reduce the increasing effort required to find suitable conference venues. Although the return to Vienna was only deemed partially successful due to price increases, Boston (which hosted ISMB 2010 and 2014) is predicted to become a 'safe' site which ISMB can periodically return to. ISMB celebrated its 20th meeting with ISMB 2012, held in Long Beach, California. This event attracted around 1,600 delegates, submitting 268 scientific papers. Richard H. Lathrop and Lawrence Hunter presented a special keynote presentation, looking back at previous ISMB meetings and attempting to predict where the field of bioinformatics may head in the future. ISMB/ECCB 2013 was held in Berlin, Germany and was attended by around 2,000 delegates, submitting 233 scientific papers. Format Main conference The main ISMB conference is usually held over three days and consists of presentations, poster sessions and keynote talks. Academic papers at ISMB were traditionally presented in a single track. Presentations at ISMB 1994 were split further into three themed days, focusing on protein secondary structure prediction, sequence analysis and AI techniques and biochemical applications, respectively. As attendance at ISMB increased, the single track approach became increasingly unsustainable and two parallel tracks were introduced at ISMB/ECCB 2004. Further expansion meant that, by ISMB 2012, over 200 talks were presented in nine parallel tracks including multiple proceedings tracks, a highlights track and a technology track. The introduction of parallel tracks to ISMB was controversial. Christopher Rawlings (head of Computational and Systems Biology at Rothamsted Research and organiser of ISMB 1995) has said: "There were a lot of people who wanted to keep it more strongly in the AI intelligent systems model and