Government data covers authoritative and valuable information about our society. Public access to government data, however, remains challenging largely due to the heterogeneity and complexity of the public information ecosystem which results in high costs for locating, decoding, inter-linking and reusing existing government data. Recently, linked data–based solutions have been adopted by the leading practitioners (such as Data.gov in the US and Data.gov.uk in the UK) to offer an open and incremental ecosystem that interconnects providers, consumers, and contributors of open government data. This article first reports a community consensus on the architecture of the linked open government data ecosystem, then reviews the key technologies reported by works included in this special issue, and finally concludes with three grand challenges towards opening, linking, and reusing government data.