home-grown software; in-house software
Computing term for software developed internally by an individual or organization, rather than purchased or outsourced.
This system runs entirely on home-grown software.
The company is developing in-house software to cut costs.
Compound of 自家製 (じかせい, 'home-made') and ソフトウェア ('software'). The term follows the pattern of 自家製 applied to various products, extended to software.