This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
I have ultrasparc machine running Ubuntu. Seems to be there's no Sun JDK available for that platforms. What other (working) platforms there exists preferably with Java5 support ? Or is the only viable solution to use Solaris ?
Here is the list of supported configurations for Sun's Java SE 5 JDK. For SPARC, there's only Solaris. As Tim says, you may have some luck with GCJ, but it does not fully support JDK 1.4 at this time, much less JDK 1.5. I have used it to run apps under linux and the performance is poor compared to Sun's.