I think it's context-dependent: I don't have insight into OSS Nokalva's use inside big companies, but in the Open Source world it certainly isn't dominant.

In Open Source, I think the biggest ASN.1 implementations I come across are OpenSSL's, libtasn1, asn1c, and then per-language implementations like pyasn1.

Most of the open source tools need patching to properly support certain scenarios (been there done that). They also lack support for parsing ASN.1 Value Notation format (textual), which is used everywhere in specifications, OSS Nokalva offers the full set of tools to handle this even with a playground and ASN.1 editor, this is non-existent in open source right now. For now the open source tools only focus on the crypto aspect, and doesn't really dive into telco, banking, biometric, and others.

Basically any commercial ASN.1 compiler prevents usage of the output in any open-source project. There is that.

https://github.com/heimdal/heimdal/tree/master/lib/asn1