1.Q: Is it possible to build the asn1c compiler on Win32? 1.A: At this point, the asn1c source code is tied to GCC-specific extensions in several key places. The CYGWIN environment with gcc compiler may be what are you looking for. Please also consider using the Online ASN.1 compiler at http://lionet.info/asn1c which generates platform-independent code. 2.Q: How to build a simplest BER (XER) encoder or decoder? 2.A: Please check the "Quick Start Guide" on ./doc/asn1c-quick.pdf Please check the "Examples" section of ./doc/asn1c-usage.pdf Also, try the following to build the X.509v3 parser: cd ./examples/sample.source.PKIX1 make ./x509dump -h -- Lev Walkin vlm@lionet.info