Restore old keyboard on Lollipop - Android Enthusiasts Stack Exchange
AOSP WiFi Keyboard - Apps on Google Play
Technical Keyboard - Apps on Google Play
Download Android 4.1 Jelly Bean Keyboard On Any 4.0.x ICS Device | Redmond Pie
Simple Keyboard is an actively developed, open source fork of the AOSP Keyboard for those looking for a less bloated, more responsive, basic keyboard with minimal permissions : r/Android
Google's iron grip on Android: Controlling open source by any means necessary | Ars Technica
Does Android Remote Desktop Client supports AOSP Androids invoking of Virtual Keyboards when focused to an input boxes? - Microsoft Q&A