Open Hardware Monitor - Monitors temperature sensors, fan speeds, voltages, load and clock speeds, with optional graph.
SmokePing - Smokeping is a tool for measuring latency.
SpeedFan - Hardware monitor for Windows that can access digital temperature sensors located on several 2-wire SMBus Serial Bus. Can access voltages and fan speeds and control fan speeds. Includes technical articles and docs.
Ping Meter Gadget - Customizable, graphical, semi-transparent ping (latency) meter.
Core Temp - Nov 4, 2017 - Core Temp is a compact, no fuss, small footprint, yet powerful program to monitor processor temperature and other vital information.
Open Nettest - Open Nettest is a platform for collecting, processing and visualizing data related QoS and QoE.