Zabbix - Track, record, alert and visualize performance and availability of IT resources
Zoho Inventory - Zoho Inventory is an online inventory management software ideal for small businesses. Simplify your inventory and order operations. Try for FREE!
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.
Stockpile - Stockpile is a free online inventory system for small business and at home uses.
Prometheus - An open-source systems monitoring and alerting toolkit.
Fishbowl Inventory - Fishbowl offers manufacturing and warehouse management solutions for QuickBooks.