What is the status of an agreement without consideration?

In general, any agreement without consideration is void. But, Section 25 of Indian Contract Act, 1872 has certain exceptions to this general rule. According to the section the following agreements without considerations are not declared void:
(a) An agreement which is made in writing and is registered and made out of natural love and affection by a person standing in near relationship.
(b) An agreement which is a promise made to compensate for something done for the promisor by a person voluntarily.  The compensation may be in whole or part.
(c) An agreement which is a promise to pay a debt which is barred by limitation.  Such promises must be in writing and signed by concerned person or his authorized agents. The promise to repay the time barred debt may be in whole or in part.