We present the four most known models for supporting the management of distributed object-orienied transactions. Although FOADmodel architecture is extensiveiy known, there is no popular implementation ofits methodology (Le.API) neither a standard model that specifies interfaces provided to end userprogrammersfor development of applicationsmanaging distributed transactions. That is why only a theory and design description will be presented Conversely, we willpresent architecture design and a brief.'description of services offered by interfaces from OTS, JTS and MT5. The MTS architecture cannot be described in detailfor commercial reasons but an approximated architecture design will be presented, based on available documenuuion: It is important to note that OTSand JTS are standards (based on the architecture of distributed objects model CORSA) proposed for the implementation of products such as transaction managers, while MTS is already a commercial producto.