MultiPath TCP, a major extension to TCP, allows the simultaneous use of a smartphone's 3G and WiFi interface to increase throughput and better resilience. We implement MultiPath TCP in the Linux Kernel, publicly available at TCP, the most used Transport Protocol on the Internet, does not allow the simultaneous usage of multiple Interfaces. Smartphones with 3G and WiFi interfaces would benefit from a simultaneous use of both interfaces. MultiPath TCP is a major extension to TCP, allowing the use of multiple Interfaces for a single data-stream, without the need to modify the applications. This allows an increased throughput and better resilience to failures. The IP Networking Lab of the Université Catholique de Louvain is implementing MultiPath TCP in the Linux Kernel. The publicly available source-code modifies/adds about 10000 lines to the Linux Kernel's TCP-stack. The implementation has shown very good performance. For example, a throughput of up to 15 Gbps across two 10 Gig interfaces, whereas regular TCP can only use a single interface and thus 10 Gbps. We are now considering inclusion in the mainline kernel and would like to encourage people to test our implementation and/or submit patches to help improving it.