Messaging apps differ on encryption by default, who you can reach, whether they run on your platform and whether the code is public. This ranking weighs privacy and encryption first, then reach and platforms, then cost.
Team chat tools differ on where they run, how much they cost as the team grows and how wide their app catalog is. This ranking weighs features and integrations first, then hosting choice, price and open-source status.
Video conferencing tools differ on meeting size, who hosts the call, whether the code is open and whether people need an app. This ranking weighs what a meeting needs to do first, then hosting and openness, then price.
Email clients differ on whether they run on phones as well as desktops, how they handle many accounts and whether the code is open. This ranking weighs core mail handling and account support first, then platform reach, privacy and price.
Whiteboard and diagramming tools differ on whether they are a live shared canvas or a diagram editor, how they store files and what they cost per person. This ranking weighs the core job first, then collaboration, storage and openness, then price.