The development of institutional structures and establishment of organizational linkages have been the weakest aspects of party development in eastern Europe. A range of parties have developed as effective electoral machines, and many have proved to be viable bases for government formation and the exercise of political power within the region’s new democratic systems. Party systems have begun to establish themselves and an ideological spectrum has crystallized that helps to anchor many of the new groupings within a recognizable, if regionally distinctive, political landscape. But many of the stronger and more stable political formations in the early years were either relics of the old establishment (communist parties in Ukraine and Moldova, or Milos˘evic´’s partially reformed socialist organization in Serbia) or their original antagonists that remained fixed in an early semi-authoritarian mode (Mec˘iar’s Movement for a Democratic Slovakia – until 1998, and Tudjman’s Croatian Democratic Union – until the end of 1999). Other newly established parties, of a more authentically pluralist nature, have generally been more unstable and less well developed in terms of organization.