Yes. Manusmriti clearly defined the relative position and the duties of the several castes, and determined the penalties to be indicted on any transgressions of the limits assigned to each of them. These laws are conceived with no sentimental scruples on the part of their authors. On the contrary, the offences committed by Brahmans against other castes are treated with remarkable clemency, whilst the punishments inflicted for trespasses on the rights of higher classes are the more severe and inhuman the lower the offender stands in the social scale.
However, the text was never universally followed or acclaimed by the vast majority of Indians in their history; it came to the world's attention through a late eighteenth-century translation by Sir William Jones, who mistakenly exaggerated both its antiquity and its importance. Today many of its ideas are popularised as the golden norm of classical Hindu law by Hindu universalists. They are, however, anathema to modern thinkers and particularly feminists.
That is what I have gathered about the Manu Smriti as well. Though it is one of the most ancient hindu texts with codified laws about the castes.
However when you say Modern thinkers and feminists, does that mean these people have aligned themselves with teachings or ideology other than Hinduism to rally against these inequities or do these people find the Manu Smiriti opposed to the Vedic teachings (which are accpeted by all streams of Hinduism). I would be most interested to see how they prove these inequities using Hindu scriptures.