I respectfully disagree with almost all that.
Ariel Diaz

Hmm — I think email is probably the hardest thing to justify doing yourself, and probably the most open standards based of the services you’ve mentioned… but the others are not governed by open standards and the more data you put into services like, for example, Slack or Trello or just about all the others, the harder it is to get away from them. I think you underestimate the danger of losing control of your organisation’s communications, thinking, strategy, and collaboration. I also think you overestimate the difficulty of setting up and managing the relevant open source services. If you’re building a business that has a software component, if your team can’t build and manage (and *integrate*) your tools into you business securely, then I’d be dubious about the prospect of that team building a credible commercial offering… If any other readers of this column finds this compelling, here are howtos for setting up many of the open source services the foundation I work for uses: https://tech.oeru.org.