It's one of the cognitive behavioural therapies most suited towards BPD. The researcher who developed it, Marsha Linehan, has BPD. From my cursory reading (review and meta-review papers) a few years ago and information from my partner's therapist both say that it's among the, if not the most, effective therapy for people with BPD.

EDIT: Some talk therapies follow a structured program, some don't. DBT, CBT, etc. are all therapies that follow a protocol. This is probably best contrasted with psychoanalysis which is not structured in the same manner and therefore not as neatly replicable. For example, I am doing a CBT for people with cPTSD and the first part was geared towards increasing my baseline. Basically working together with my therapist to commit to and engage in pleasurable activities, and activities for building mastery. After that we started the second part where we accumulated and analyzed my behaviours and thinking patterns. I am in the third part now where we are challenging those negative and unhelpful thoughts (this is the cognitive part) and sort of updating them with more accurate thoughts (ones that aren't maladaptive).