nmon - This systems administrator, tuner, benchmark tool gives you a huge amount of important performance...

Chargebee - Chargebee lets you manage subscriptions and payments at scale, handle custom recurring billing scenarios, reduce subscription churn and simplify accounting.

gtop - System monitoring dashboard for terminal

Chargify - Chargify is the best online billing software for all of your Recurring Billing needs. Learn more about simplifying your Subscription Billing today.

psutil - psutil is a module providing an interface for retrieving information on all running processes and...

Recurly - Subscription billing and recurring billing management. Recurly offers enterprise-class subscription billing for thousands of companies worldwide.