Input4MIPs validation is a validation library, specifically focussed on input4MIPs data (https://pcmdi.llnl.gov/mips/input4MIPs/). It is provided, by default, as a library. If you wish to use it as an application, we recommend installing the locked version of the package, i.e. input4mips-validation-locked, because this pins the versions of key dependencies (which avoids breakages because of updates to dependencies).