On August 10th, 2023 HashiCorp, the company behind open source and open core projects such as Terraform, Vault, Nomad and Consul switched the license for Terraform and other software from the MPL to the Business Source License (v1.1), that is usually considered a non-open source license. That license contains a clause that prohibits companies from using Terraform if they offer a "competing" (to HashiCorp) product, where the definition of "competing" is so vague that many people in the community would rather stop using Terraform than get into legal troubles.
BSL 1.1 is a "source-available" license that allows copying, modification, redistribution, non-commercial use, and commercial use under specific conditions. Companies like Couchbase, Cockroach Labs, Sentry, and MariaDB, which developed this license in 2013, have switched to the BSL.
In a reaction to HashiCorp's move many companies, people and entities in the Infrastructure as Code (IaC) space have signed the OpenTF Manifesto lead by Gruntwork that has written their own Terraform Add-on called Terragrunt. Gruntwork CEO Yevgeniy Brinkman has followed up with a blog post called The future of Terraform must be open. Over 100 companies, 10 projects, and 400 individuals pledged their time and resources to keep Terraform open-source and appealed to HashiCorp to return Terraform to the community and revert the license change they were making for this project.