Free Pascal was actually on the shortlist of SARC, together with Ada and D [1]. We had different requirements though: GUI was not an issue as we have our own GUI; neither was an IDE. What was very important in our case was D’s compile time reflection capabilities which has enabled us to implement (de)serialisation to/from the binary format that the old Pascal implementation produced. In the maritime industries it is important to be able to build on projects that were developed in the past.
Pascal is not a bad language for engineering, in some aspects it is even better than D. Still, the combined features of D made it a winner over all, in our case.
What would these compilers have as advantage over the existing compilers?
Back when there was just one D compiler the common complaint was that this was too few. Now that there are three you sometimes read that there are too many. This is the first time I see someone needing more :)
I work for another company also putting its eggs in the D basket (SARC). We do not consider this risky because of two main reasons:
1) D is not dependent on the funding of one big corporation, so our future is not at the mercy of such corporation.
2) Three highly compatible compilers exist, all of them libre. Inclusion into gcc is probably the best insurance for any language.
The D community may be comparatively small, but for us it is big enough. Changes in and around the language may happen comparatively slowly, but for us they happen fast enough. Tooling may be comparatively limited, but we are actually rather impressed by what is available.