Random linear network coding (RLNC) is a popular coding scheme for improving communication and content distribution over lossy channels. For packet streaming applications, such as video streaming and general IP packet streams, recent research has shown that sliding window RLNC approaches can reduce the in-order delay compared with block-based RLNC. However, existing sliding window RLNC approaches have prohibitive computational complexity or require feedback from the receivers to the sender. We introduce caterpillar RLNC (CRLNC), a practical finite sliding window RLNC approach that does not require feedback. CRLNC requires only simple modifications of the encoded packet structure and elementary pre-processing steps of the received coded packets before feeding the received coding coefficients and symbols into a standard block-based RLNC decoder. We demonstrate through extensive simulations that CRLNC achieves the reliability and low computational complexity of block-based RLNC, while achieving the low in-order delays of sliding window RLNC.