Recent development of diamond field emitter cathodes and devices fabricated from molding process is presented. Practical modifications involving the sp(2) content, surface treatment, boron doping, and tip sharpening to further enhance diamond field emission are discussed. A new fabrication process for achieving ultrasharp diamond tips with a radius of curvature less than 5 nm has been achieved and shows significant improvement in emission characteristics. Discussion of this enhanced emission in diamond microtips is presented in accordance with analysis of emission behavior. The development of high site density of uniform diamond microtip arrays is presented. We also report the development of a new technique to fabricate self-aligned gate diamond emitter diodes, which achieve very high emission characteristics at extremely low applied voltage. The latest development aims to integrate diamond field emitters with silicon-based MEMS processing technology and achieve totally monolithic diamond field emitter devices on silicon wafers. Preliminary results in the triode-configuration demonstrate promising transistor characteristics suitable for vacuum microelectronic applications.