There are several well known software applications available for M&A. Some of these software e.g. Midaxo, eknow and Mergerware provide the entire range from managing M&A deal flow to managing M&A data through VDRs and integration. Others are specific to the theme. A few examples under each: For managing M&A Pipeline – DealCloud, iLevel, eFront, zapflow;
For VDRs: This is a long list but some of the ones I have used or heard of are ansarada, intralinks, box, iDeals and datarooms. For integration, these are the same as used for project management such as smartsheet, teamwork, Microsoft Projects, Sharepoint, workfront and so on.
Hope this helps.