This work explores user interfaces and algorithms for recognizing freeform sketching in digital ink. Like other recognition work before it, it is based on the premise that an increased understanding of the ink results in increased utility to the user. Interpreted digital ink is preferable to physical ink for its archival, search, editing, and simulation capabilities and its relative ease of integration with existing computer applications. However, unlike previous recognition work it also posits that a computer should never obstruct the user’s thought capture in creative scenarios. In other words, the primary goal of a pen computer should be to unobtrusively capture freeform digital ink; the user should not be concerned with how the ink will be interpreted. These claims are validated by considering three separate scenarios in detail: note-taking in meetings, annotating digital documents with markup, and sketching diagrams. For each of these common tasks, recognition should be flexible enough to incorporate the writing and drawing styles of an individual user, yet accurate enough to satisfy the scenarios for which it was intended. To this end, I have developed several algorithms that attempt to satisfy these constraints.