Features We Can't Implement

Licensing restrictions
We cannot ship Audacity with the following features due to the manufacturers of the technology enforcing non-disclosure clauses in their licensing agreements:


 * ASIO Support: We could create an ASIO version of Audacity quite easily, but if we distributed it with its source code, we would be breaking the Steinberg license agreement, and if we distributed it without the source code we would be breaking the licenses for Audacity and all the other libraries it relies on. Audacity 1.3.3 and later can be compiled from source code on Windows with the ASIO SDK to give ASIO support, but this is on the strict understanding that this ASIO enabled build must not be distributed in any way. Our inability to distribute pre-compiled versions of Audacity with ASIO support will remain until Steinberg relaxes licensing. See ASIO Audio Interface for more information.


 * Rewire is a proprietary technology owned by Propellerheads Software AB that permits real-time streaming of audio data between applications, typically between Propellerheads' Reason sequencing software and a mixer application such as Cubase. As with ASIO, the Rewire licensing agreement requires non-disclosure of their software code, which is contrary to the open-source licence that Audacity is distributed under. As a result Audacity cannot implement Rewire support.

Circumvented restriction

 * Import/Export WMA files: This restriction imposed by Microsoft has been worked around in current Audacity by use of the FFmpeg library.


 * VST GUI support: This restriction imposed by Steinberg prevented VST effects displaying their full customised interface. It has been worked around in current Audacity by using an open source VST header.

Other
For more details and alternative programs, see Will there be a mobile version of Audacity for iPod, iPad or other smartphones? in our Frequently Asked Questions (FAQ).
 * Mobile devices/operating systems: Unfortunately, we can't support these at present, partly due to the processing power and disk space requirements of Audacity, and partly because the interface library we use doesn't support mobile operating systems yet.