A Gretl developer works on the open-source software package Gretl, used for econometric analysis. They write and debug code, improve the software’s functionality, and ensure its user-friendliness. They also create new features to facilitate data analysis, like tools for model estimation, testing, and forecasting. Additionally, they write documentation and provide user support. They collaborate with other developers, statisticians, and econometricians, ensuring the software meets the needs of its users. A Gretl developer needs strong programming skills, particularly in C, and a deep understanding of econometrics and statistical methodologies. They also constantly update their knowledge to stay abreast with the latest technological developments.