Accessible to Everyone vs. Accessible to Every Computer

I have recently been eval­u­at­ing a cou­ple of dif­fer­ent pieces of online meeting/collaboration soft­ware. At this point we are look­ing at 2 dif­fer­ent options– iVo­cal­ize because of its low cost and sim­ple (acces­si­ble) inter­face and Hori­zon­Live which has more fea­tures and is cross-platform. iVo­cal­ize is cur­rently PC-only. There are other fac­tors involved, but those seems to be the major issues. (If any­one is aware of any other cross-platform or fully acces­si­ble solu­tions, please let me know!)

While I think either would work for our needs– it presents an inter­est­ing dilemna, do we exclude Mac and Linux users or some users with dis­abil­i­ties? (Hori­zon­Live has many acces­si­ble com­po­nents, but the num­ber of fea­tures on the soft­ware and the way they are imple­mented would likely be daunt­ing for users with visual or intel­lec­tual dis­abil­ties). True, many users with dis­abil­i­ties would be able to access Hori­zon­Live with litte or no prob­lem, but Mac users could also use iVo­cal­ize with Vir­tu­alPC or by using another com­puter. Another con­found­ing vari­able is that both pieces of soft­ware will be improv­ing in the com­ing months and undoubt­edly other viable options will come into the picture.

Any­one want to shed some light on the topic (or con­found things a lit­tle more). Please com­ment if you have any thoughts, thanks.