This makefile example demonstrates how to automate the compilation of LaTeX and XeLaTeX documents, including full bibliography support through BibLaTeX and biber. It shows separate build targets for standard LaTeX and XeLaTeX workflows, each with and without bibliography processing, as well as a clean target to remove auxiliary files. The makefile uses the `pdflatex` and `xelatex` commands with specific flags for synctex and nonstopmode, while managing build artifacts in a hidden `.build` directory. It copies source and `.bib` files into the build directory before running the appropriate compiler sequence, then moves the final PDF back to the project root. The code relies on standard Unix utilities like `mkdir`, `cp`, `mv`, and `rm` within Make’s recipe syntax.