ProLaw is a case law management and Accounting software package designed for law firms... but also quite usable by government agencies! ProLaw stores data in a Microsoft SQL Server database and is a Thomson Elite product.
The latest version (v11) is quite stable and is used by a majority of ProLaw firms. There are still firms running v9 and even v7, which are versions that were released over a dozen years ago.
ProLaw is also very customizable. Although it doesn't have an API--and having worked at ProLaw/Thomson-Elite for 8 years, the word was always that they would never create an API--ProLaw allows a wide variety of automation and customization. Examples of ProLaw automation and ProLaw tools demonstrate the types of ProLaw automation and ProLaw customization possible.