Self-assembled Quantum Dots (QDs)have great potential as the active region in semiconductor laser diodes, resonant cavity light emitting diodes and semiconductor optical amplifiers. Yet, after nearly a decade of intense research many of the promised advantages have yet to be fully achieved. In this paper it will be shown that this non-ideal behavior is the result of an inability to control the size, shape and composition of the three dimensional islands during growth and factors such as carrier relaxation, which are fundamental to the lasing process, are not well udnerstood. In addition, the presence of the wetting layer and non-radiative recombination centers incorporated in the barrier material during growth at temperatures below that normally used for high quality material lead to poor performance at high temperatures. The emphasis has recently shifted towards GaAs-based devices operating at telecomms wavelengths where there is the possibility of replacing InP-based emitters and fabricating vertical cavity lasers in the 1.3 and 1.55-micron wavelength regions. The progress here has been steady and it is likely that commercial products will be available soon. There are also encouraging indicators for single photon emitters utilizing single dots and wideband semiconductor optical amplifiers.