As have been seen, integral and differential systems in function spaces are ideal mathematical models in many applied problems stemmed from engineering, physics, electronics, fluid dynamics, biotechnology, aero-astrodynamics, chemical technology, population dynamics, medicine, and economics. They have in recent years been major objects of investigations with fast increasing interest. This special issue is dedicated to the dissemination of current significant progresses and new trends in this field. The main focus of this issue is the Cauchy problem for nonlinear integral and differential systems in abstract spaces and related boundary problems as well as inverse problems. Articles devoted to important problems in the field are welcome. Topics of interest include, but are not limited to:

• Existence, uniqueness, and regularity
• Delay and fractional differential systems
• Related theory of function spaces
• Euler and Volterra systems
• Topological and monotone methods, including fixed point methods, topological degree methods, and maximum (minimum) methods
• Related theory of operator families
• Stability, approximation, and asymptotic behavior including periodicity, almost periodicity, and almost automorphy of solutions
• Systems with discrete or continuous time
• Related control problems
• Applications to mathematical physics, engineering, fluid dynamics, biology, and other real-world phenomena

Before submission authors should carefully read over the journal's Author Guidelines, which are located at http://www.hindawi.com/journals/jfsa/guidelines/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/submit/journals/jfs/ids/ according to the following timetable: