Update file README.md

README.md

@@ -20,9 +20,9 @@ Key course pages:
 References and resources:
 * [GitLab Flavored Markdown (GFM)](https://docs.gitlab.com/ee/user/markdown.html)
 * [Java Archive (.jar)](https://docs.oracle.com/javase/tutorial/deployment/jar/basicsindex.html) for sharable/runnable software libraries
-* [Java SE JDK download](https://openjdk.java.net) (OpenJDK 20) or
+* [Java SE JDK download](https://openjdk.java.net) (OpenJDK 21.0.1) or
   [Java SE JDK download](https://www.oracle.com/technetwork/java/javase/downloads/index.html) (OracleJDK 20)
-* [Netbeans](http://www.netbeans.org) (version 17), [Using Git Support in NetBeans IDE](https://netbeans.org/kb/docs/ide/git.html)
+* [Netbeans](http://www.netbeans.org) (version 19), [Using Git Support in NetBeans IDE](https://netbeans.org/kb/docs/ide/git.html)
 and [Video of Cloning a Git Repository Using NetBeans IDE](https://netbeans.org/kb/docs/ide/git_nb_ssh_screencast.html)
 * [Open-DIS Repository](https://github.com/open-dis) (specifically [opendis7-java](https://github.com/open-dis/opendis7-java)) and [Distributed Interactive Simulation: The Missing Handbook](https://github.com/open-dis/DISTutorial/blob/master/README.md)
 * [Savage Developers Guide](https://savage.nps.edu/Savage/developers.html) resources for [Cygwin](https://savage.nps.edu/Savage/developers.html#Cygwin), [DIS](https://savage.nps.edu/Savage/developers.html#DIS) and [telnet](https://savage.nps.edu/Savage/developers.html#telnet)