Usman Saleem is a seasoned software developer with special focus on Java, JEE, PostgreSQL, and utilizing open source tools in software development in general. He has worked with EnterpriseDB, OpenSCG, Red Hat, and Ventyx, Australia. He has taught object-oriented programming and enterprise software development in several public and private sector universities to undergraduate students. When he is not (re)writing his blog software, he likes trying out various strength training workouts or playing Angry Birds with his son.
Usman has an MSc (CS) degree and holds RHCSA, SCWCD, SCBCD, SCJD, and SCJP certifications. He maintains his blog at http://www.usmans.info.
Otávio Santana (@otaviojava) is a developer and enthusiast of open source. He is an evangelist and practitioner of agile philosophy and polyglot development in Brazil. Otávio is a JUG leader of JavaBahia and SouJava and a strong supporter of Java communities in Brazil, where he also leads the BrasilJUGs initiative to incorporate Brazilian JUGs into joint activities. He is a cocreator and is also responsible for the Linguagil Group—a merge of Java, Ruby, Python, and Agile groups that promote agility across language-focused communities. In the open source world, Otávio is a developer in OpenJDK and a creator of Apache Easy-Cassandra. He has also helped in JBoss Weld, Hibernate, Apache Commons, and other open source projects. Otávio is a very active speaker in Brazil, where he has participated in the largest Java events in the country. As an international speaker, Otávio has presented in JavaOne and the Cassandra tour events. Otávio is also a writer and has many articles and even a book on JVM Internals. Otávio Santana actually means "make the future Java", working in several Java Specification Request (JSR), JAR, as part of the Java Expert team. Otávio was recently nominated and won JCP's Outstanding Adopt-a-JSR Participant of the Year award for his very active role in several JSRs and OpenJDK.
Martin Toshev is a software engineer by profession and hobby. He has been working on a number of large enterprise projects for different companies for the past 5 years using mostly the Java technology stack. He has experience in the areas of social networking and J2EE middleware and is a contributor to the OpenJDK platform.