AltaCast is described as 'continuation of the Oddcast/Edcast streaming software that can stream to either Icecast or SHOUTcast servers' and is an app in the Audio & Music category. There are four alternatives to AltaCast for Windows, Mac and Linux. The best alternative is butt, which is both free and Open Source. Other great apps like AltaCast are LadioCast (Free), Rocket Broadcaster (Freemium) and SAM Cast (Paid).
butt (broadcast using this tool) is an easy to use, multi OS streaming tool. It supports ShoutCast and IceCast and runs on Linux, MacOS and Windows. The main purpose of butt is to stream live audio data from your computers Mic or Line input
LadioCast is a software running on Mac OS X to stream digital audio such as Internet radio program. It has the following features: * Icecast, RTMP and SHOUTcast audio source streaming. * Ability to transmit audio streaming to multiple servers simultaneously.