There are a number of software titles that are available at the organizational level (Enterprise Software). These do not require individual licenses nor purchasing. There are also software titles that can be purchased at a discounted rate due to academic pricing and/or leveraging the buying power of UNL. These can be found in this procurement catalog: Software Catalog. Individual departments may provide access to additional software options.
In general, there is a preference that users use tools that are already within existing Enterprise systems (such as Office Suite applications). Should you need software that is not from these sources, you will need to go through a risk review process. In some cases, a program or service you want may have already been reviewed. Check with ITS and Procurement to find out.