There are several open source components in devolopment to be used in the eCars. These components are branded as eComponents.
Small microcontroller-board, with suitable hardware and software to communicate with motor controllers, eBMS and in-car CAN-systems. It has no operating system, just highly tuned software running in "endless loop". For example, it's responsible of taking voltage measurements from electronic power-pedal and communicating with motor-controller to translate drivers will to suitable communication commands for the motor-controller. Basically, eECU is there for the car and for the system. Drivers doesn't see it or even know it's there. Working prototype is currently installed in eCorolla.
Small form-factor PC (for now, we are using an Asus 7" eeePC laptop with solid-state flash drives). It communicates with eECU and shows information about the system in 7" touch-screen LCD. User interface is scalable, so it should work on any screen. It has remote operating possibility build in, so it can be used even with wireless or mobile-phone connections to the car. This is intended to "high-end" conversions, with enough space to mount the screen etc. Working prototype is currently installed in eCorolla.
Small microcontroller-board, with embedded small display and joystick. It's capable of communicating directly to motor controller and eBMS, showing important information to the drivers. A little bit more limited in capabilities than full eECU+eGUI combination, but this small board should be just fine for "budget" conversions. It replaces both eECU and eGUI, and provides cost-effective way to see what's going on in the system.
Battery Management System for Lithium batteries. Will contain quite sophisticated hardware, capable of transferring power from "strong" cells to the "weaker" ones, to help them be better balanced. Doesn't contain resistors to turn excess energy to heat as many of OSS-BMS competitors seem to do - instead it consumes and transfers all the energy available via small DC-DC transformer in each cell. Visit the home page of eBMS project.
Audio feedback for the driver. Important question when EV's "key is turned" the first time - "is it REALLY on?" This component should answer to that question, in a way that haven't yet seen done in DIY EV's - with an nice audio-sample. It should give driver the feeling that this conversion is really something different and for example even user interface issues have been thought very carefully. And if something is wrong with the system, the melody is a little bit different. User can just plug this component to the home-computer and download new melodies for the eCar. Or even make own melodies This component can be combined with either eECU, eGUI (full) or eGUI (mini).