R' Eliezer says: From the time the Temple was destroyed Shavuos is like the Sabbath.  Rabban Gamliel says: Rosh Hashanah and Yom Kippur are like the festivals.  The Sages, however, do not agree with either of the two. Rather, Shavuos is like the festivals; Rosh Hashanah and Yom Kippur are like the Sabbath.

Garments may not be rent, shoulders may not be bared, and the mourner's meal may not be served, except by relatives of the deceased. The mourner's meal is only served on a set-up bed.  We may not bring [food] to the house of mourning neither on a tray, nor on a salver, nor in a decorative basket, but only in [plain] baskets.  We do not say the mourner's blessing during [Chol] HaMoed, but we stand in rows and offer consolation. They then dismiss the public.