When looking for low maintenance and a solution suited for all kinds of pc applications. It is great when you are looking to store physical files in folder locations and you can then reference the document in the database. It has an open-source community around it along with documentation for third-party drivers of the development environment.
Usability has improved by unifying the architecture. The only thing's missing out of the box is a simple GUI DB tool for viewing DB contents and maybe running some SQL queries.
It is cost-effective, maintenance-free, easy to deploy and use on Linux and Windows environments and it works steadily. It has an open-source license. Installing Oracle was quite difficult in comparison to Firebird.