s concerns about oil and coal use continue to mount, public opinion is changing in favor of using biofuels in homes, vehicles, and industrial applications. With this shift in public opinion comes more innovation. Patent applications, which are one measure of innovation in a particular field, are dramatically increasing in numbers in the area of biotechonology, and specifically in the areas of so-called first-, second-, and third-generation biofuels. In general, when patents and patent applications are reviewed, it is instructive to keep a few points in mind. There are two types of published patent applications: those that have issued and those that have published but are still pending and under examination. This article will take a look at both. A discussion of what each of these groups of publications mean is helpful. An issued patent has a fixed set of claims at the end of the patent, that defines the invention, regardless of what is included in the detailed description section. Issued patents are in force 20 years from the filing date, and they give the patent owner the right to exclude others from making, using, and/or selling the claimed invention in the country where the patent issued. Published patent applications are useful to provide notice to the general public as to potential future patents and their scope. Patent applications are published 18 months after the first filing date and can be useful for both the inventors and competitors. Thus, between the filing date or priority date of the application and the publication date, the patent application is not published, and therefore, not readily available to the public for review. Inventors use pending patent publications to put likely competitors on notice that they may have enforceable patent rights at some point in the future. Competitors use patent publications to scope out the technology landscape. It is important to note, however, that the existence of a patent publication does not necessarily mean that a patent will issue from that application or that the final issued set of claims will look anything like the claims in the publication. As such, patent publications should be used primarily for notice and information purposes. A review of the current state of the patent art related to biofuels and biofuel technology quickly makes clear an exponential increase in the number of applications in these areas. The patent publications coming out now are based on applications filed around the end of 2007/beginning of 2008, which was before the last significant spike in oil prices. There is no doubt that the number of patent publications going forward will increase given that these will be based on patent applications filed after January 2008. Many, if not most, of the applications in this field are focused on two primary subjects: what to use to create a biofuel and how to process a material to produce a biofuel. As with most developments in the energy field, efficiency is the key to new developments. Is the material an efficient source of biofuel? Is the process used to produce the biofuel efficient? Is the combustion of the biofuel efficient? As will become clear in discussion of recent patent publications, improving efficiency is at the heart of each of these technologies. (Please note, this paper is neither advocating nor determining the patentability of any of these technologies. The content of this article is directed to an objective summary of some of the biofuel-related patent art.)