Netconf-console - console application for interacting with NETCONF servers built on top of ncclient
Openstack-utils - helper utilities for OpenStack services on Fedora/RHEL distros
Netshot - configuration and compliance management for network devices
BLT - BGP Linkstate Topology. Gathers your network topology using BGP-LS, and nicely draws it in realtime.
Postman - Chrome application to query REST APIs
Atom - text editor
Beyond Compare (paid) - compare files
eNMS - "an open source web application designed to help automate networks graphically"