We design and implement an information announcement basic software toolkit that realizes a new using style in mobile computing. This style regards a mobile computer as a server as well as a client. The proposed toolkit has two features. One is that the toolkit can solve problems such as disconnections and narrow network bandwidth. The other is that the toolkit allows a wide variety of legacy network applications designed for stationary environments to be adapted to mobile environments easily and smoothly. In this paper, we design an information announcement toolkit that supports the construction of information announcement systems from mobile computers. In addition, through implementing server applications on the toolkit, we show that the system works well and gives useful environment to clients.