Someone said consumer apps (Carousel and Mailbox in this case) couldn&#x27;t be open-sourced because they use &quot;internal&quot; APIs.<p>My point was just that any API over HTTP that&#x27;s used by a consumer app is <i>not</i> private or internal. It is a public API with unfriendly documentation.<p>(Note that when I say &quot;unfriendly documentation,&quot; I&#x27;m not even talking about sniffing. Most consumer apps can be decompiled by non-experts, and then the text-based API calls would be readable.)