Webel: SysML4Mathematica: Cameo Systems Modeler: Can perform calculations with a custom Quantity ValueType (for Mathematica) directly, but DOES NOT perform units-aware algebra (no automatic conversions)
Webel: Psy/MPsy: Psychrometrics for Mathematica: Due to Mathematica's units-aware Quantity algebra system it is irrelevant what units are used for the input Quantities for creation of the MPsy objects, as long as they are dimensionally consistent!
Mathematica: The Webel Units` package has Quantity variables for frequently used units using a naming convention 'unit$[Symbol]' or 'unit[DescriptiveName]' or unit[Acronym], each with a corresponding '$unit...' for the units identifier String(s).
Mathematica: The awesome Quantity system for values with units is everything the SysMLv1.x Quantity/Unit system should have been (and hopefully SysMLv2 will be). But it comes at a high performance cost!
