Our files are fully compatible with the XLIFF standard and therefore can be opened with anything in the world that supports XLIFF.
The problem with XLIFF in Trados happens because SDL uses different abbreviations for the language codes for some languages. It is the problem on the Trados side, not from the Smartcat files. There is a workaround to solve this problem - the XLIFF files can be opened in a text editor and the language codes can be replaced by the Trados-compatible language codes. Files will then be compatible with Trados.