OpenNMS sounds like a wonderful piece of software, will let you know when I get done installing it. The installation instructions for Windows leave a great deal of information out, so I'm going to make a list as I figure it out.
1. Install Sun Java SDK 5 or higher from http://java.sun.com/javase/downloads/?intcmp=1281. Must be the SDK or SE edition which includes the JDK as well as the JRE. Default install works fine.
2. Install Apache Tomcat 5.5 from http://tomcat.apache.org/download-55.cgi, default install is OK.
3. Install PostgreSQL from http://wwwmaster.postgresql.org/download/mirrors-ftp?file=%2Fbinary%2Fv8.2.6%2Fwin32%2Fpostgresql-8.2.6-2.zip, default install is OK.
4. Download JICMP from http://sourceforge.net/project/showfiles.php?group_id=4141&package_id=240236, unzip and place the two files (.jar & .dll) in the Java jdk\bin directory.
5. Install the opennms-installer-1.5.90.jar from http://sourceforge.net/project/showfiles.php?group_id=4141. When you download, you should be able to save it as a .jar file, and when you doouble-click on the .jar file it should execute. If it doesn't then you need to go back to step 1 and locate the proper Java SDK installation.
6. Open a cmd prompt at "c:\program files\OpenNMS\bin" (assuming you installed everything with defaults, adjust as needed). type "opennms.bat start" and enter. You should get many lines of commands scrolling by over the next few moments.
7. Open IE and open "http://localhost:8980/opennms". user "admin" pwd "admin", strongly urge you to change it immediately by going to "Admin", "Configure Users, Groups and Roles", "Configure Users", "Modify", "Reset Password". Be sure to click the "Finish " button at the bottom of the page to save changes.
I'm already impressed, while I was resetting the admin password (and typing these instructions) it has already found 7 nodes on the network. I'm already in love with it.
After another 5 minutes it has found 33 nodes, it is just pinging addresses in order going thru the subnets.
Well, it only took me two hours to get this far. I think I have spent more than 80 hours with Cacti, and I have just a few things graphed. At this point I would say that OpenNMS shows great promise.