What language are the alsa configuration files (such as ~/.asoundrc) written in?

Here’s a brief snippet of an alsa config file (/usr/share/alsa/pcm/default.conf):

pcm.!default {
        @args [ CARD ]
        @args.CARD {
                type string
                default {
                        @func getenv
                        vars [
                                ALSA_PCM_CARD
                                ALSA_CARD
                        ]
                        default {
                                @func refer
                                name defaults.pcm.card
                        }
                }
        }
...

Does this language exist outside of alsa, and if so, what language is it?