ety of hardware platforms, operating systems, and networks. Central to PCS 1.0 was support for Intel's Indeo compression algorithm and Microsoft's DVI graphics/video interface. The document conferencing specification mirrored the features offered by Intel's ProShare family of personal conferencing products. The PCWG came under fire by opponents (read Intel) who accused it for trying to derail the ITU-T's document conferencing standards effort. The IMTC launched an aggressive effort to force the PCWG to support the de jure standards-setting activities of the ITU-T. In response, the PCWG announced that PCS 2.0 would provide support for the ITU-T's Rec. H.320 and Rec. T.120. Intel defended the PCWG's decision to ignore H.320 in favor of Indeo. It noted that H.320 was a room-system oriented compression algorithm that was too complex for many desktop systems to implement economically. Indeo, a compression-only codec, can be inexpensively added to desktops. This argument took a blow in February 1995, when Microsoft announced support for ITU-T standards. In May 1996, the Personal Conferencing Work Group (PCWG) agreed to construct the PCS 2.0 specification such that desktop conferencing products initiate calls to other systems using H.320 and T.120. If, after call initiation, the PCS 2.0 software discovers that the called system also supports PCS 2.0 then the software would communicate in the PCS (Indeo/ProShare) mode. The PCWG's acquiescence settled a long-standing battle on the desktop conferencing standards-front and cleared the way for wide acceptance of the ITU-T T.120 standard. A number of corporations, that had been waiting to see whether the PCWG or T.120 would prevail, signed orders. Most desktop video communication products on the market now support the T.120 family of data conferencing specifications. T.120-AN INTRODUCTION T.120 is an ITU-T standard that defines point-to-point and multipoint document conferencing over a variety of transmission media. Like H.320, T.120 is an umbrella standard. It is a model tha