Plattner contributed more than €20 million which enabled reconstruction of the historic exterior of the Stadtschloss (in Potsdam), which had damaged during World War II and demolished in 1959. At the time, it the largest donation ever gifted in Germany by a single individual. Plattner signed The Giving Pledge in February 2013. He also helped in the establishment of the Museum Barberini, which from January 2017 on will exhibit Hasso Plattner’s collection of artworks from the former German Democratic Republic and as well as special exhibitions.
Also in 1998, Plattner founded the Hasso Plattner Institute for software systems engineering based at the University of Potsdam, and in Palo Alto, California, its sole source of funding being the non-profit Hasso Plattner Foundation for Software Systems Engineering. Plattner has pledged €50 million of his personal fortune over a period of 20 years. Since its foundation, Plattner's commitment to the HPI has quadrupled to over €200 million. He not only fully finances the HPI, but is also actively involved as a Director and lecturer in Enterprise Platforms and Integration Concepts.
For his commitment to economics and science, Plattner has received a number of honours. Germany's manager magazin awarded its Leadership Award for Global Integration to the "technology guru" and inaugurated him into their Hall of Fame, which honours those who promote economic and social development in Germany. In 2001, Time Magazine Europe ranked Plattner #1 on its list of the most important and influential IT personalities.
Since his retirement from SAP, Plattner has been particularly active as a benefactor in the field of technological research. Media reports have named him one of Germany's most important private sponsors of scientific research. Plattner received his honorary doctorate in 2002 and his honorary professorship in 2004 from the University of Potsdam. Plattner had also received an honorary doctorate (1990) and an honorary professorship in Information Systems (1994) from the Saarland University, Saarbrücken. The same university named him an honorary senator in 1998.
His donation of €6 million for the Isombululo programme for the prevention and treatment of HIV/AIDS was announced at the Presidents Cup, one of the world's leading international golf tournaments in 2003 and it is suggested that this amount will have helped 360,000 people. In the spring of 2005, Plattner personally covered the costs of the 46664 benefit concert, which took place at his Gary Player-designed golf course, The Links of Fancourt in George which is near Cape Town and which was broadcast globally on television. Proceeds went towards the former South African President Nelson Mandela's fund to fight HIV/AIDS.
On 21 January 2004, at a ceremony at the Hasso Plattner Institute celebrating the 60th birthday of its founder, German Chancellor Gerhard Schröder made the following comments on Plattner’s achievements: "We need more Hasso Plattners and more SAPs in order to get Germany moving again economically." According to the Chancellor, Plattner created an international corporation proving "that German companies can be at the top of the technological hierarchy worldwide". In an interview in August 2004, the Munich-based management consultant Roland Berger named Hasso Plattner as one of the five Germans who have made the greatest impression on him. In the Welt am Sonntag article Berger pointed out how Plattner founded, built up and adapted SAP to a changing market was a "master achievement". In 2016, Plattner was estimated to be worth US$10.8 billion by Forbes.
HassoPlattnerVentures, a venture capital fund, was set up with more than 25 million euros on 1 July 2005 in Potsdam with the goal of supporting young entrepreneurs in transforming their ideas into marketable products. As of December 2009 HPV manages €150 million and has 17 companies in its portfolio. An affiliate fund, HPV Africa, was founded in 2008 with €29 million, and has already invested in five companies. Plattner provides the lion's share of this investment capital.