The BCF development includes both, a XML file format as well as a RESTful webservice.
The BIM Collaboration Format (BCF) is an open file XML format that supports workflow communication in BIM processes. "bcfXML v2" which became released in October 2014 replaces the earlier "bcfXML v1".
The RESTful webservice (bcfAPI) enables software applications to exchange BCF data seamlessly in BIM workflows.
Before 2010, endusers, who wanted to exchange issues, proposals and change requests in BIM-data-models, always had to exchange the whole BIM-model as a bulk data. The receiver had to compare different releases of the BIM-model in order to filter the requests from the sender. As a much more efficient way to support this effort the idea of developing an open standard to enable BIM-workflow communication between different software tools had been proposed to buildingSMART. In 2010, Tekla and Solibri came up with an initial XML schema, called "bcfXML v1", to encode messages containing BIM-topics (e.g. issues, proposals, change requests, ...) addressed in BIM-data-models. The implication was to boost the degree of collaboration in BIM-workflows by only exchanging the lean topics and not the entire bulk BIM-data model between software applications. "bcfXML v1" became implemented by several software packages and valuable experiences could be gained by using it in BIM-based projects.
In 2013, based on these experiences a task force, lead by Solibri, was established in buildingSMART's ISG (Implementer Support Group) to enhance "bcfXML v1" in certain focal points like flexibility related to project specific aspects, the possibility to exchange maschine readable BCF-Topics with attached BIM-Snippets (small components of a BIM-model), attached multiple viewpoints, ... . Finally and after intense public review "bcfXML v2" became released and was adopted by buildingSMART in October 2014.
In 2014, as a second major objective of the BCF-task force, the BCF-webservice "bcfAPI v1" was introduced by iabi (Institute of applied Building Informatics). The idea behind this is to exchange BCF-Topics not only manually or by e-mail attachments via bcfXML-files, but seamlessly and automated via a standardized RESTful API. "bcfAPI v1" is currently in the status of a Release Candidate 1 and the final release is scheduled for February 2015.