For the upcoming 6.6 release of asn1c (due out in early 2013), we are improving our support for the 2008 revision of the ASN.1 standards. The improvements fall into two categories: new ASN.1 types and extended XER encoding instructions.
First, we are adding support for new types OID-IRI and RELATIVE-OID-IRI.
Second, while we have indirectly supported EXTENDED-XER via direct compilation of XSD for some time, we have also been gradually adding support for using the XER encoding instructions in ASN.1. In version 6.6, we are adding support for GLOBAL-DEFAULTS MODIFIED-ENCODINGS, TEXT, and UNTAGGED.
Besides the above, the 2008 revision also added the TIME type, which is supported by the current version of asn1c. Thus, the only 2008 features that will be left unsupported as of asn1c version 6.6 are: most of the XER encoding instructions and the PER encoding instructions.