|Some in Gaza have praised Hamas' achievements as a resistance movement [EPA]
On December 14, 1987, Sheikh Ahmed Yassin and Mohammad Taha, two prominent members of the Muslim Brotherhood in Gaza, formed the Harakat al-Muqawama al-Islamiya
, Hamas, as an alternative to the Palestine Liberation Organisation (PLO).
From the outset, Hamas wove its way into the socio-economic Palestinian fabric by operating social welfare programmes, running hospitals and schools, and providing for the families of killed fighters.
Since the first and second intifadas (1987 and 2000, respectively), Hamas has gained political power culminating in its surprise 2006 parliamentary elections win.
However, Israel, the EU and the US refused to recognise Hamas' electoral win and heavily favoured dealing with the Fatah movement of the PLO.
In June 2007, hostilities between Fatah and Hamas broke out leading to an ousting of the latter's parliamentarians from the West Bank.
Tenstion continues between Fatah and Hamas.
Hamas is listed as a terrorist organisation by the US, Canada, the UK and is banned in Jordan.
Israel blames Hamas for home-made rocket attacks launched from the Gaza Strip and has enforced a stranglehold siege of the territory for more than a year.
Human rights organisations have criticised the siege saying it has deprived ordinary Palestinians of fuel, basic foods and medicines and could plunge the territory into a humanitarian crisis.
Al Jazeera spoke to Palestinians in Gaza about Hamas' 21 years in power and what lies ahead.
Majed Abdullah, 55, former university professor in the US
"I think that Hamas restored the Palestinian issue to its Islamic roots despite Israeli efforts to the contrary. Hamas restored the culture of resistance which was buried by the successive so-called peace accords.
We now know which Arab governments really support the Palestinian issue and which don't.
Hamas has offered meaningful contributions to the Palestinian resistance effort despite what the international community says about it. What has the international community done for the Palestinian people except label Hamas as a terrorist organisation?
As concerns the Hamas-Fatah political argument ... well, what is happening is not between Hamas and Fatah, but between Hamas and those who rule Fatah for the sake of the illusive peace process - people I call the 'the Oslo Team'.
I do not see a future for internal dialogue between Hamas and Fatah but I am hopeful regarding the creation of a Palestinian state as our current democratic leaders seem to be steadfast to the principles of Palestinian statehood."
Mofeed Ahmed, 35, journalist
"Twenty-one years is not a long time in the annals of history. Nevertheless, Hamas' achievements during these years are considerable when compared with other revolutionary movements across the world.
It started as a small resistance group, then it became an active opposition party and within years it could become the main party when it achieved an overwhelming victory in the parliamentary elections.
No one can deny that the presence of a group like Hamas helped Palestinians return to their national resistance, but its political direction may not have served our dreams of resistance as we had hoped.
However, we can say that it tried to merge between policy and resistance and it would be a very good thing if it succeeded to do so.
We do need a mediator to help solve the problems between Hamas and Fatah; an objective mediator. Egypt does not ideally fit this role because it is subject to Israeli and American pressures. Ultimately, the Egyptians will support whichever side has signed many peace and security accords with the Israelis.
There need to be fundamental regional changes that accept the idea of a Palestinian nation beside an Israeli nation. And this is not a difficult thing to happen."
Wael al-Mana'mi, 37, university instructor
"Hamas is an Islamic resistance movement which was borne of many different secular and leftist movements in the Palestinian arena. I think it grew in popularity so quickly because of the Islamic culture of the Palestinians.
I also believe it came about in a time when national resistance ceased to be an imperative for secular and leftist movements.
For example, all the military wings of these aforementioned movements feel they have no rational ideology to follow and as a result have adopted Islamic resistance, which Hamas was first to use.
When it comes to the question of the homemade rockets fired at Israel, these Qassam rockets are simple, but they are considered a prominent achievement for the Palestinian resistance.
These simple weapons, which were acquired by all other Palestinian fighters as well, have forced the Israelis to ask many different mediators to do their utmost in order to convince Hamas to prohibit their use.
However, we are today a nation divided.
The political argument between Hamas and Fatah has resulted in an unprecedented Palestinian division and both sides bear the responsibility of this.
I would also fault the occupation and the international community which supports one side at the expense of the other.
Fatah and Hamas fight each other but it is us, the average people, who have to suffer. They fight for what they think is for everything - power - and in the meantime, we have nothing.
But if they prioritise the points of agreement between each other, they will agree and unite with each other.
And for the Palestinian state, it is a dream that will be achieved after a long time as it needs great efforts, not only from the Palestinians, but also from many other regional sides."
Ghasan al-Shami, 28, public relations officer
"What Hamas has shown from the day when it started until today proves that it is committed steadfastly to its principles. It started as a small movement from the mosques, from small groups fighting with stones, formed more extended groups fighting with guns, (martyrdom operations) and then rockets, became a main opposition party and then the main party in the parliament.
Hamas survived several crises starting with the imprisonment of all its leaders in the early stages of its foundations by the Israeli occupation, the strict strike in 1996 by the Palestinian Authority and at the end the assassination of most of its founders.
All this happened in 21 years. So that, aside from its religious attitude, it is considered as a great achievement and it should be a model to be followed by others.
Unfortunately, Fatah did not live up to its pledges of handing over control after the parliamentary elections. Fatah is still governing all the security apparatuses and everything inside the different ministries.
That resulted in a two-headed government - Hamas in Gaza and Fatah in the West Bank.
I think that the internal dialogue and the political argument between both Hamas and Fatah will end when both consider the national benefit is better than their personal benefit.
I'm sorry but there can't be a Palestinian state without the reformation of the PLO."
Jameel Megbel, 45, school headmaster
"I think that Hamas has achieved something unbelievable if we are to compare its short age with its huge accomplishments. But I think that it should have given way to the groups which have historically led the Palestinians and consequently have more experience in managing the conflict with the Israelis.
Hamas won the elections in 2006, but the world imposed a siege against it trying to pressure it to step aside and let others form policy.
This was the international community's mistake which gave rise to the internal Fatah-Hamas conflict you see today.
I think that both sides should meet each other with trustful intention to reconcile and let the common good of their people overcome their personal benefit.
I hope that both sides will end hostility to each other and agree on one liberation programme because the alternative is perpetual warfare which we will not see the end of.
It is then, and only then, that we can begin to see the dream of a Palestinian state bear fruit."
Source: Al Jazeera