Many Twitter users also demanded similar penal action against former Pakistan Prime Minister Nawaz Sharif.
#musharraf trended with 9,892 tweets.
One user wrote: "Congratulations Pakistan! Whether this penalty is enforced or not is yet to be seen but this is big. First time in our history. Hats off to the brave judges!"
"End of military misadventures in Pakistan as Musharraf gets death for treason. Long live the Constitution," a user posted.
Another wrote: "After Musharaf's death sentence from court, it's the turn to hang Sharif khandan for forgery, corruption, murder of civil, leaking country's secrets, and facilitating terrorists in our country. Is it enough to hang them?"
A post read: "Historic & unprecedented verdict by any of the Pakistani courts against any military dictator. I think the superior court will turn down the capital punishment if Musharraf goes for appeal but I must say the special court has done a daring & courageous job. Good job."
A Twitter user remarked: "Democracy won, dictatorship lost."
A Musharraf supporter commented: "Wow!!! Nawaz Sharif looted all our money but is now having fun in the UK but the man who made incredible contribution to Pakistani defence and economy awarded death sentence?"
Another said: "Sad day in the history of Pakistan, where a judgment has been given without hearing the defendant. Also, General Musharraf has been singled out in this case shows the malafide intention of Nawaz Sharif and Iftikhar Chaudhary. Justice must be seen to be done!"
( With inputs from IANS )