We present the main improvements and new features in version $\texttt{2.0}$ of the open-source $\texttt{C++}$ library $\texttt{FireFly}$ for the interpolation of rational functions. This includes algorithmic improvements, e.g. a hybrid algorithm for dense and sparse rational functions and an algorithm to identify and remove univariate factors. The new version is applied to a Feynman-integral reduction to showcase the runtime improvements achieved. Moreover, $\texttt{FireFly}$ now supports parallelization with $\texttt{MPI}$ and offers new tools like a parser for expressions or an executable for the insertion of replacement tables.

中文翻译：

---

$\texttt{FireFly}$ 中密集和稀疏有理函数的插值和其他改进

我们介绍了开源 $\texttt{C++}$ 库 $\texttt{FireFly}$ 版本 $\texttt{2.0}$ 中用于有理函数插值的主要改进和新功能。这包括算法改进，例如用于密集和稀疏有理函数的混合算法以及用于识别和去除单变量因素的算法。新版本应用于费曼积分归约，以展示所实现的运行时改进。此外，$\texttt{FireFly}$ 现在支持与 $\texttt{MPI}$ 的并行化，并提供新的工具，如表达式解析器或用于插入替换表的可执行文件。