Unlike Gustavo Gutierrez, Leonardo Boff, a Brazilian theologian currently serving as Professor Emeritus at Rio de Janeiro State University, never became mainstreamed on the same level. Boff, for whichever reason, was much more rough and overt with his message - he expressed not just solidarity or sympathy for communist regimes but overt support. He maintained a controversial role in the Catholic Church for repeatedly denouncing the church's structure as a "hierarchy" and "fundamentalist." In the 2000s, he compared George W. Bush and Ariel Sharon to "fundamentalist terrorist states," saying also similar things for the emirs and kings of the Arabian peninsula.
"Terrorist" was a favorite pejorative for Boff to hurl out and he did just so toward Cardinal Joseph Ratzinger during the 1980s, resulting in his being censored by the church for a year. Like Gutierrez, he and the larger camp of liberation theologies were censored and kept at a distance until the election of Pope Francis. Boff had very good things to say about the election of Francis, adding that Francis still is conservative in many respects but that "I am encouraged by this choice, viewing it as a pledge for a church of simplicity and of ecological ideals."
Boff extended liberation theology well beyond the handful of books that Gutierrez published however. Boff continued with the message of a "preferential option for the poor" even when it was patently unpopular, such as in the 1990s. In the middle of that decade, he published Ecology and Poverty: Cry of the Earth, Cry of the Poor, a treatise on how liberation theology can answer climate change and other environmental problems. The concept that poverty is structured runs in to liberation theology's ecological commentary as well - many poor parts of the world have incomplete or absent physical structure protecting them against environmental calamity. While the rich can deny the problem, the poor have to make plans for surviving it.
A good deal of commentators noted how Laudato Si, Pope Francis' encyclical on climate change, took a bold break from most climate change activists like Al Gore in moralizing and humanizing the problem. Boff's work was doing this well before Jorge Bergoglio was even a candidate for the papacy - when it was unpopular both in the church and in the wider culture.
Boff's praise for Francis only became more overt after Laudato Si. Boff has since said that Francis has the ability to "change the church." Boff may already have done so.