Silat they say, came from Indonesia through into Malaysia and then into the Filipines long ago. Influencing the fighting styles of the Filipinos as well as spreading Islam particularly in the South. All Silat systems I know of use knives and use them well. As well as Karambit. Most Silat systems I know of have Pole, stick and Sarong practice in them. Pre Silat as we now know it, it is said that settlers came from India and brought with them their own style fighting arts which influenced Silat.
Kali, Arnis, Escrima in many styles are the hybrid styles influenced earlier by Silat. Kali also acquired some Spanish fencing influence later on. Kali concentrates equally on Stick fighting and Knife fighting. Empty hand skills in Kali resemble Silat skills but with much less exaggerated movement as the more traditional "Animal" styles of Silat. The Empty hand skills of both Kali and Silat are often relative to knife techniques. Kali has stick, hand, knife and pole techniques. Kali also has a sort of CQC simple kinda kick boxing and a sort of wrestling in the theory of Dumog.
However, there are many Family styles of Silat who have much less traditional and exaggerated Animal movements as well.
Kuntao or Kuntao Silat I believe are the Hybrids of Southern Chinese close quarters styles who came via trade to Indonesia, the Filipines and Malaysia. Chinese and say Indonesian Silat combined are what can make up a Kuntao Silat system.
Over time and with WW2 via occupation, etc the Japanese have also had influence on these countries introducing Jiu Jitsu, Judo and Karate into the mix.
Now you can find many Silat styles with familiar Japanese techniques and influences.
However, Silat is considered particularly Indo, Malay and Kali is particularly Filipino.