GRUB - Multiboot boot loader
Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
EasyBCD - EasyBCD is NeoSmart Technologies multiple award-winning answer to tweaking Windows bootloader.
AppDynamics - Get real-time insight from your apps using Application Performance Management—how they’re being used, how they’re performing, where they need help.
Grub2Win - Safely dual boot Windows and Linux without touching the Windows MBR.
Zabbix - Track, record, alert and visualize performance and availability of IT resources