Deprecating Mono

Octopus plans to phase out support for Mono in future releases, prompting users who deploy to SSH targets via Mono to transition to .NET Core. Mono, a CLI virtual machine enabling .NET code execution on non-Windows platforms, has been integral to Octopus since 2015 for Linux deployments. However, with the rise of .NET Core as the dominant cross-platform framework, the cost of maintaining Mono, including development, testing, and support expenses, now outweighs its benefits. Octopus will begin warning users of the upcoming changes in version 2023.2, with functionality being disabled by default starting from version 2023.4. Users are encouraged to switch to the self-contained Calamari (.NET Core) option by adjusting their deployment target configurations, which typically requires minimal changes. While most users will experience minor impacts, specific platforms such as RHEL6 and FreeBSD may require additional attention or upgrades. The overall goal is to modernize the deployment process by eliminating dependencies on older technologies like Mono.