they don't see to really care about having it being able to encode arbitrary data structures

I think that's an unkind assumption about intent. (N.B. I am the current maintainer.)

But like JSON, BSON is document-oriented, so is not designed to store raw arrays or scalars the way Storable or Sereal will. So in that sense, it might not be the right choice for your needs.

Beyond that however, the goal of BSON is to handle whatever you can throw at it as best as possible given the ambiguities mapping data between a dynamic, largely typeless language like Perl and a typed data format like BSON. Knowing that some Perl scalar is binary data and not an arbitrary string is impossible without some hints from the programmer.

The MongoDB::BSON implementation is in XS and has been part of the MongoDB driver distribution. We hope to eventually split it out so that it can be used independently where warranted.

The BSON.pm implementation is pure Perl and was originally developed outside MongoDB (but has since been adopted by the company). There are still some areas where it is not yet as good as MongoDB::BSON.

Even if BSON is not right for this particular problem, if anyone experiences bugs using either implementation, I encourage you to report them or at least email us about them so we can fix them.

-xdg