Complex sentence: Wikimedia is one of the largest and most prominent users, with a community whose goals to make available the free and open sharing of knowledge are closely aligned with those of CC, so the needs of the Wikimedia communities are an important consideration for CC.
Split into simpler sentences: Wikimedia is one of the largest and most prominent users, with a community whose goals to make available the free and open sharing of knowledge are closely aligned with those of CC. So the needs of the Wikimedia communities are an important consideration for CC.