The Birth and Marriage records I merged together from Archive.org, The Texas Department of Vital Statistics, and Rootsweb.com. They've been extensively cleaned (especially the marriage records). Nonsense entries have been removed, formatting has been made consistent, duplicate records combined, etc. These records are still not 100% complete or accurate, but as far as I'm aware, it's the best source currently available for free on the internet.
The Death and Divorce records are less comprehensive and are only the records that are (or were previously) available on on the Texas Department of Vital Statistics Homepage. No cleaning/combining/etc has been done to Death or Divorce records.