VMware Content Packs and Extractors - including Memory/CPU/Storage /LDAP Login/Bad Login/Security Events Network snooping, and much more! Graylog 6x+, Hypervisor and Vcenter Appliance.
Pure Java Network Tools - Ping, Trace, Telnet-client, DNS-check, IP-calculator, Syslog-Server, ARP-cache, Network Ping-Scanner, ICMP-flood, UDP-flood, TFTP-server ...