The paper presents the experimental realization of a universal linear optical processor (LPU) capable of implementing all possible linear optical protocols up to six modes. The LPU consists of a six-mode system integrated on a photonic chip, featuring 15 Mach-Zehnder interferometers and 30 thermo-optic phase shifters, which can be reconfigured to perform various quantum information protocols. The authors demonstrate the versatility of the LPU by implementing heralded quantum logic gates, entangling gates, boson sampling, and complex Hadamard operations. They achieve high fidelities in these experiments, with an average fidelity of 0.999 ± 0.001 for 100 Haar random unitaries. The LPU's ability to switch between different protocols in seconds highlights its potential for applications in fundamental science and quantum technologies. The paper also discusses the theoretical foundations of linear optics and the experimental methods used to characterize the LPU, including quantum process tomography and error analysis.The paper presents the experimental realization of a universal linear optical processor (LPU) capable of implementing all possible linear optical protocols up to six modes. The LPU consists of a six-mode system integrated on a photonic chip, featuring 15 Mach-Zehnder interferometers and 30 thermo-optic phase shifters, which can be reconfigured to perform various quantum information protocols. The authors demonstrate the versatility of the LPU by implementing heralded quantum logic gates, entangling gates, boson sampling, and complex Hadamard operations. They achieve high fidelities in these experiments, with an average fidelity of 0.999 ± 0.001 for 100 Haar random unitaries. The LPU's ability to switch between different protocols in seconds highlights its potential for applications in fundamental science and quantum technologies. The paper also discusses the theoretical foundations of linear optics and the experimental methods used to characterize the LPU, including quantum process tomography and error analysis.