When it comes to describing something as most liberalizing, there are plenty of synonyms to choose from depending on the context. You might consider using words like progressive, empowering, transformative, innovative, or even revolutionary. If you're trying to convey a sense of openness, you could use terms like inclusive, tolerant, accepting, or diverse. Descriptions like these might be used to describe policies or movements promoting social justice, political reforms or technological advancements that dismantle barriers to freedom and equality. Ultimately, the word you choose will depend on the specific meaning you hope to convey.